Article

Forms of Variable Resistance Training

February 2009
Strength & Conditioning Journal 31(1):50-64

February 2009
31(1):50-64

DOI:10.1519/SSC.0b013e318195ad32

Authors:

Daniel Travis McMaster

The University of Waikato

John Cronin

Auckland University of Technology

RESISTANCE TRAINING METHODS HAVE BEEN BROADLY CLASSIFIED INTO 3 CATEGORIES: CONSTANT, ACCOMMODATING, AND VARIABLE RESISTANCE. VARIABLE RESISTANCE TRAINING METHODS, WHICH INCLUDES CAMS AND LEVERS, CHAINS, AND RUBBER-BASED RESISTANCE, WILL BE THE FOCUS OF THIS ARTICLE. THE KINEMATICS, KINETICS, AND HUMAN STRENGTH CURVE CHARACTERISTICS ASSOCIATED WITH THESE 3 TYPES OF VARIABLE RESISTANCE ARE DISCUSSED, GIVEN THAT EACH RESISTANCE TYPE MAY OFFER A UNIQUE SET OF MECHANICAL STIMULI AND, HENCE, MUSCULOSKELETAL ADAPTATIONS. THE PRACTICAL APPLICATIONS AND LIMITATIONS ASSOCIATED WITH EACH FORM OF VARIABLE RESISTANCE WILL ALSO BE CONSIDERED.

The Use of Free Weight Squats in Sports: A Narrative Review—Terminology and Biomechanics

Article

Full-text available

Feb 2024

Abstract: There is substantial evidence indicating that increased maximum strength as a result of training with squats, particularly full and parallel squats, is associated with superior athletic capabilities, such as sprinting, jumping and agility. Although full and parallel squats have been strongly associated with sport performance, there is also some evidence that the use of partial squats may provide angle specific adaptations that are likely advantageous for specific sporting activities. Partial squats may be particularly advantageous when trained in conjunction with full or parallel squats, as this practice results in a greater training effect. There is a paucity of evidence that squatting is associated with excessive injuries to the knees, lower back, or other structures. Evidence does indicate that squatting, including full squats, can be undertaken safely, provided an appropriate training methodology is applied. Indeed, based on scientific data, the cost/benefit ratio indicates that squats should be recommended and should be a central strength training exercise for the preparation of athletes in most sports, particularly those requiring strong and powerful whole body and lower body movements.

Effects of lower-extremity explosive strength on youth judo athletes adopting different types of power-based resistance training OPEN ACCESS EDITED BY

Thesis

Full-text available

Mar 2023

Objective: The present study compared the effects of two different resistance types (pneumatic resistance and free weight) of 6-week squat training on the performance for young female judo athletes in linear speed and vertical jump by utilizing the maximum power of each set of squats in each training session as the monitoring vehicle. Monitoring data were used to assess the effects and trends of the two resistance types on 70% 1RM weight-bearing during the 6-week intervention training. Methods: In a 6 weeks squat training (2 reps/week with a constant load), 23 adolescent female judo athletes (Age span: 13-16 years, 14.58 ± 0.96) were randomly selected and then divided into the traditional barbell (FW) group (n = 12) and the pneumatic resistance (PN) (n = 11) group according to different resistance types (free weight and pneumatic resistance), with 10 in FW group and 9 in PN group actually completed the study. Before and after training, the 30-m Sprint time (T-30M), vertical jump height and relative power (countermovement jump, static-squat jump, and drop jump), reactive strength index (DJ-RSI), and maximal strength were assessed. One-Way ANOVA was used to examine the pre-test differences of groups (FW and PN). A 2-factor mixed-model analysis of variance was used to examine the independent effects of group (FW and PN) and time (pre and post) on each dependent measure. Scheffe post hoc comparisons were used to examine the differences. Pre-and post-experimental differences between the two groups were analyzed using independent samples t-tests and magnitude-based inferences (MBI) derived from their p values, and effect statistics were applied to compare the pre-and post-changes exhibited by each group to identify the potential beneficiary groups. Results: The PN group outperformed the FW group in terms of maximal power output per training session (822.5 ± 55.22 vs. 927.42 ± 48.15, conventional vs. pneumatic, p < 0.001, effect size = −2.02). After 6 weeks of training, the FW group showed significant increases in vertical jump height and relative strength (CMJ, SJ, DJ), with no significant gains observed in T-30 and maximal strength. The PN group showed significant improvements in maximal strength; however, no significant improvements were observed in the other tests. In addition, there was no significant difference in DJ-RSI between the two groups before and after training. (2023), Effects of lower-extremity explosive strength on youth judo athletes adopting different types of power-based resistance training.

Connective Adaptive Resistance Exercise (CARE) Machines for Accentuated Eccentric and Eccentric‑Only Exercise: Introduction to an Emerging Concept

Article

Full-text available

Apr 2023
SPORTS MED

Eccentric resistance exercise emphasizes active muscle lengthening against resistance. In the past 15 years, researchers and practitioners have expressed considerable interest in accentuated eccentric (i.e., eccentric overload) and eccentric-only resistance exercise as strategies for enhancing performance and preventing and rehabilitating injuries. However, delivery of eccentric resistance exercise has been challenging because of equipment limitations. Previously, we briefly introduced the concept of connected adaptive resistance exercise (CARE)—the integration of software and hardware to provide a resistance that adjusts in real time and in response to the individual’s volitional force within and between repetitions. The aim of the current paper is to expand this discussion and explain the potential for CARE technology to improve the delivery of eccentric resistance exercise in various settings. First, we overview existing resistance exercise equipment and highlight its limitations for delivering eccentric resistance exercise. Second, we describe CARE and explain how it can accomplish accentuated eccentric and eccentric-only resistance exercise in a new way. We supplement this discussion with preliminary data collected with CARE technology in laboratory and non-laboratory environments. Finally, we discuss the potential for CARE technology to deliver eccentric resistance exercise for various purposes, e.g., research studies, rehabilitation programs, and home-based or telehealth interventions. Overall, CARE technology appears to permit completion of eccentric resistance exercise feasibly in both laboratory and non-laboratory environments and thus has implications for researchers and practitioners in the fields of sports medicine, physiotherapy, exercise physiology, and strength and conditioning. Nevertheless, formal investigations into the impact of CARE technology on participation in eccentric resistance exercise and clinical outcomes are still required. Supplementary Information The online version contains supplementary material available at 10.1007/s40279-023-01842-z.

Effects of lower-extremity explosive strength on youth judo athletes adopting different types of power-based resistance training

Article

Full-text available

Mar 2023

Exercise Technique: The Landmine Row

Article

Full-text available

Nov 2022

The landmine row is an upper-body pulling exercise using a barbell as a lever. This column provides the strength and conditioning coach with a summary of trained musculature, technique descriptions for common landmine row variations, suggested instructional cues for improving technique and performance, an overview of unique exercise biomechanics, and programming recommendations.

Effects of Variable-Resistance Training Versus Constant-Resistance Training on Maximum Strength: A Systematic Review and Meta-Analysis

Article

Full-text available

Jul 2022
Int J Environ Res Publ Health

Greater muscular strength is generally associated with superior sports performance, for example, in jumping, sprinting, and throwing. This meta-analysis aims to compare the effects of variable-resistance training (VRT) and constant-resistance training (CRT) on the maximum strength of trained and untrained subjects. PubMed, Web of Science, and Google Scholar were comprehensively searched to identify relevant studies published up to January 2022. Fourteen studies that met the inclusion criteria were used for the systematic review and meta-analysis. Data regarding training status, training modality, and type of outcome measure were extracted for the analyses. The Cochrane Collaboration tool was used to assess the risk of bias. The pooled outcome showed improved maximum strength with VRT, which was significantly higher than that with CRT (ES = 0.80; 95% CI: 0.42–1.19) for all the subjects. In addition, trained subjects experienced greater maximum-strength improvements with VRT than with CRT (ES = 0.57; 95% CI: 0.22–0.93). Based on subgroup analyses, maximum-strength improvement with a VRT load of ≥80% of 1 repetition maximum (1RM) was significantly higher than that with CRT (ES = 0.76; 95% CI: 0.37–1.16) in trained subjects, while no significant differences were found between VRT and CRT for maximum-strength improvement when the load was

Comparative analysis of a bench press using strength methods with and without intra-repetition variable resistance

Article

Full-text available

Mar 2022

Background: In line with the recommendations for sustainable development, SDG 3 highlights the importance of working on health and well-being. In this respect, strength training has proven to be highly effective. Improved physical performance in most sports is associated with increased maximum dynamic strength. The existing literature on strength training methods is extensive, varied and has a certain tradition in the scientific field. Therefore, the regulation and optimal treatment of the load/stimulus with which one works in the development of strength is a key point. The analysis and study of the variability in loads or training stimuli is essential since it is modified according to the objective of the training and adapted to the circumstances. The aim of this study was to compare the differences measured in average and maximum strength, rate of force development (RFD) and the perception of effort (RPE) between two training methods (constant resistance (CR) vs. intra-repetition variable resistance (IRVR) in a bench press. Methods: Due to the methodological difficulties involved in generating an IRVR, fifteen men executed different percentages of one maximum repetition (40%, 60%, 80% and 100%) with CR and IRVR. The percentage to graduate the selected load was 20% of variable resistance. An intra-subject design was used to compare the acute differences between intra-repetition variable resistance and constant resistance. Results: The results showed significant differences in IRVR for maximum force at 1RM (p = 0.001). A significant decrease in RPE with IRVR was documented for all percentages evaluated (p = 0.011). Less accumulated load during execution with IRVR in the first phases of the range of motion (ROM), provides a greater acceleration of the external load, consequently, in the last phase of the concentric extension a faster speed is produced compared to the traditional method with CR (p = 0.036). Conclusion: IRVR method requires a lower load accumulated in the first phase of the ROM allows more acceleration of the external load and therefore overcome the sticking point with a higher velocity. The constant adaptations in the pattern of strength production during the ROM cause the muscles to stay closer to their best "length-tension" ratio in the concentric phase; therefore, they can generate higher levels of strength. In addition, the results obtained show that the IRVR method requires less perceived effort. For all these reasons, it should be considered an effective method for developing maximum dynamic force, mainly for sub-maximum and maximum loads.

Equipment and Training Devices

Chapter

Oct 2021

Recent classifications of resistance training methods classify them in gravitational, to move the resistance we will have to apply an acceleration greater than the force of the gravity (9.81 m·s⁻¹), and non-gravitational methods that allow us to work in multiple directions, not being exclusively conditioned by gravity. Bodyweights training, also known as calisthenic exercise; Free-weights training, weight lifting through barbells, dumbbells, and kettlebells; inertial devices, how flywheel devices that an active stretch, while trying to brake an external resistance that exceeds the capacity of the muscle; and external resistance variable resistance, where resistance varies throughout range of motion are, among others, the main methods of resistance training currently. In this chapter, a contextualization of them will be carried out, exposing those essential aspects that it is necessary to know from a practical application and allowing the reader to understand the following chapters where each of them will be addressed in depth.

Comparison of traditional and accommodating resistance training with chains on muscular adaptations in young men

Article

Jan 2021

Background: Providing accommodating resistance with the use of chains (CRT) is a programming technique that may enhance muscle size, strength, and power. However, there is a paucity of studies comparing the responses to CRT and traditional resistance training (TRT) approaches. This study aimed to examine the effects of 8 weeks of CRT and TRT on muscular adaptations in young recreationally-trained men. Methods: Thirty men (26 ± 4 y) volunteered to participate in the present study and were randomly assigned to either CRT (n = 10), TRT (n = 10), or a non-exercise control group (CG, n = 10). A resistancetraining program (3-4 sets, ~8-12 repetitions at 65-80% of 1RM) was performed three times a week for 8 weeks. Percentage body fat, arm and thigh circumferences, 1RM and endurance (number of repetitions to failure 60% of 1RM) strength tests in the back squat and bench press exercises, and vertical jump power were assessed before and after the intervention. Results: Following the intervention, both training groups demonstrated improvements in strength compared to CG, where greater gains were observed for CRT (e.g., bench press 1RM: CRT=28%; TRT=19% / back squat endurance: CRT=8%; TRT=2%). Conclusions: The use of chains during resistance training may promote greater gains in strength in young men.

Análisis comparativo del press de banca utilizando métodos de fuerza con y sin resistencia variable intra-repetición

Thesis

Full-text available

Apr 2016

Training Specificity for Athletes: Emphasis on Strength-Power Training: A Narrative Review

Article

Full-text available

Nov 2022

Specificity has two major components: A strength-endurance continuum (S-EC) and adherence to principles of Dynamic Correspondence. Available evidence indicates the existence of the S-EC continuum from two aspects. Indeed, the S-EC exists, particularly if work is equated as a high load low repetition scheme at one end (strength stimulus) and high volume (HIEE stimulus) at the other. Furthermore, some evidence also indicates that the continuum as a repetition paradigm with high-load, low repetition at one end (strength stimulus) and a high repetition, low load at the other end. The second paradigm is most apparent under three conditions: (1) ecological validity—in the real world, work is not equated, (2) use of absolute loads in testing and (3) a substantial difference in the repetitions used in training (for example 2–5 repetitions versus ≥10 repetitions). Additionally, adherence to the principles and criteria of dynamic correspondence allows for greater “transfer of training” to performance measures. Typically, and logically, in order to optimize transfer, training athletes requires a reasonable development of capacities (i.e., structure, metabolism, neural aspects, etc.) before more specific training takes place

Comparing the effects of variable and traditional resistance training on maximal strength and muscle power in healthy adults: A systematic review and meta-analysis

Article

Full-text available

Aug 2022
J SCI MED SPORT

Objectives The aim of the study was to systematically screen the literature and aggregate different effects between variable resistance training (VRT) and traditional resistance training (TRT) on maximal muscle strength and muscle power and identify potential sex- and training program-related moderator variables. Method A systematic literature search was conducted in SPORTDiscus, PubMed, and Web of Science. Interventions were included if they compared VRT and TRT in healthy adults and examined the effects on measures of maximal muscle strength and/or muscle power of the lower and/or upper body. A random-effects model was used to calculate weighted and averaged standardized mean differences (SMD). Additionally, univariate sub-group analyses were independently computed for sex and training-related moderator variables. Results Seventeen studies comprising a total of 491 participants (341 men and 150 women, age 18–37 years) were included in the analyses. In terms of maximal muscle strength, there were no statistically significant differences between VRT and TRT for the lower (p = 0.46, SMD = -0.10) or the upper body (p = 0.14, SMD = -0.17). Additionally, there were no significant training-related differences in muscle power for the lower (p = 0.16, SMD = 0.21) or upper body (p = 0.81, SMD = 0.05). Sub-group analyses showed a significant moderator effect for training period and repetitions per set for maximal muscle strength in the lower body (p = 0.03–0.04) with larger strength gains following TRT when performing more repetitions per set (p = 0.02, SMD = 0.43). No other significant sub-group effects were found (p = 0.18–0.82). Conclusions Our results suggest that VRT and TRT are equally effective in improving maximal muscle strength and muscle power in healthy adults.

Hamstring Torque, Velocity and Power Elastic Band Measurements during Hip Extension and Knee Flexion

Article

Full-text available

Nov 2021

The quantitative dynamic monitoring of the performance of hamstring muscles during rehabilitation and training cannot currently be undertaken using elastic resistance bands. Hip extension with a fully extended knee involves hamstring agonists, while knee flexion involves only the hamstring. The purpose of this study is to provide normative values of torque, velocity and power involving hamstring muscles opposing elastic bands. Twenty amateur athletes aged 25.7 ± 4.9, were studied during two motor tasks—hip extension and knee flexion, both isometric & dynamic—with an elastic resistance band and DINABANG portable instrument. We compared the peak isometric torque in hip extension with agonists (2.93 Nm/kg) and without them (1.21 Nm/kg): the difference is significant. The peak angular limb velocity—starting at 50% of the maximum torque—is smaller in hip extension with agonists (215.96°/s) than in a knee flexion without them (452.56°/s). The combination of peak torque and peak velocity estimates power and there is no difference (p = 0.051) with and without agonists: 452.56°Nm/s.kg without agonists and 542.13°Nm/s.kg with them. This study opens the possibility of monitoring torque–velocity–power profiles for hamstring exercise in open chain.

Maximal isometric force in the start of the first pull exhibits greater correlations with weightlifting performance than in the mid-thigh position in national and international weightlifters

Article

Full-text available

Jul 2021

This investigation compared the maximal isometric force capacity between the start position of the first pull (IPSP) and isometric mid-thigh pull (IMTP), and their relationship with weightlifting competition performance in twenty national and international, male and female weightlifters. Isometric strength assessment and competition performance data collected as part of the routine sport science services of a national weightlifting performance programme were used for this study. Differences in isometric peak force (PkF) and allometrically scaled peak force (PkFa) between the IPSP and IMTP were evaluated using a paired-samples t-test. The relationships between absolute and allometrically scaled IPSP, IMTP, Total (TOT), Snatch (SN) and Clean & Jerk (CJ) variables were analysed using Pearson's Product-Moment Correlation. Fisher's r-to-z transformation was used to statistically compare the correlation values between the IPSP and IMTP with weightlifting performance measures. The IMTP PkF and PkFa were significantly greater than the IPSP PkF and PkFa, respectively, across combined (COM), male (M) and female (F) groups (p = < 0.001). However, the IPSP PkF exhibited significantly greater correlations with SN (r = 0.94 vs. 0.83, p < 0.05) and TOT (r = 0.95 vs. 0.86, p < 0.05) than the IMTP PkF in the COM group. In addition, the IPSP PkFa exhibited a significantly greater correlation with allometrically scaled snatch (SNa) (r = 0.83 vs. 0.51, p < 0.05) than the IMTP PkFa in the COM group. No significant correlations were observed between the IPSP PkFa and IMTP PkFa across M, F and COM groups. These findings suggest that the maximal force capacity in the IPSP is a greater determinant of weightlifting performance than in the IMTP, however, each may be representative of independent neuromuscular qualities. Coaches and practitioners working with weightlifters may consider implementing the IPSP assessment in addition to the IMTP to evaluate the strength characteristics specific to the different phases of the pull.

The Effect of TheraBand® Corrective Exercise on Co-contraction of Ankle Joint in Men with Genu Valgum during Walking: A Randomized Clinical Trial Study

Article

Full-text available

Apr 2020

Introduction: Malalignments in the lower limb can affect the biomechanics of human movements such as walking. The ankle joint has a major role in shock absorption, however abnormalities such as genu valgum can disrupt its function. The objective in this study is to investigate the effect of corrective exercise with ThraBand® on the ankle joint co-contraction in patients with genu valgum during walking. Materials and Methods: 24 male students (20-30 years old) were randomly divided into the two control and experimental groups. Corrective exercises were performed for 8 weeks using TheraBand® for the experimental group. The electrical activity of the selected muscles was recorded by the electromyography (ECG) device (Biometrics Ltd, UK). The statistical analysis was performed using the SPSS software and repeated measures analysis of variance (ANOVA) at the significant level of 0.050. Results: Findings in the experimental group showed that the general co-contraction of ankle joint increased significantly in the heel contact phase during the post-test phase compared to the pre-test phase (P = 0.044; d = 0.12). Other components did not show any significant differences (P > 0.050). Conclusion: Generally, increased co-contraction of ankle during the heel contact phase indicated greater ankle joint support after the corrective exercise.

Acute Effects of Combining Weight and Elastic Resistance Exercise on Vascular Function in Older Adults

Article

Full-text available

Apr 2024

Prior research has suggested that resistance exercise may result in a temporary decrease in vascular function, as measured by flow-mediated dilation (FMD), among untrained young individuals. However, the immediate impact of combined elastic and weight resistance training on older adults remains insufficiently explored. We assessed vascular function before, after, and 30 min after acute exercise under three resistance conditions to evaluate whether a combination of weight and elastic resistance exercises has an acute effect on vascular function in older adults. Fourteen older adults (65.6 ± 2.9 years) executed three sets of 12 repetitions at 65% of one repetition maximum (1 RM) of the bench press (BP) exercise. Testing was performed on three separate days as follows: (1) barbell alone (BA); (2) barbell plus elastic bands (10% of 65% 1 RM) (BE10); and (3) barbell plus elastic bands (20% of 65% 1 RM) (BE20). A two-way (time × condition) repeated measures analysis of variance was employed to assess the time and condition effects on flow-mediated dilation (FMD) and pulse wave velocity (PWV). At 0 min post-exercise, FMD was significantly higher during BE10 than during BA (p < 0.05); however, at 30 min post-exercise, no significant difference (p ≥ 0.05) was observed between the three conditions. In each condition, FMD results did not differ significantly at different times (p ≥ 0.05). For FMD, the main effect of the condition (F[2,26] = 3.86, p = 0.034) and that of the time and condition (F[4,52] = 3.66, p = 0.011) were significant. For PWV, only the difference between the BA and BE10 conditions was significant at 0 min (p < 0.05). PWV increased from baseline in the BA condition (p < 0.05) but not significantly in the BE10 and BE20 conditions (p ≥ 0.05). Therefore, BA, BE10, and BE20 demonstrated various changes in vascular function. Long-term training intervention studies are needed to validate these findings.

Efeitos do treinamento com resistência elástica nos idosos: Revisão de literatura

Article

Full-text available

Nov 2023

Exercícios usando materiais para resistência elástica tem alcançado um lugar considerável na sistematização no treinamento resistido, contudo, dependendo da sua situação, use padrões de deslocamento mais funcionais compatíveis à máquina de musculação. Esta revisão teve como objetivo em analisar os métodos de treinamento resistido com faixa elástica em idosos, podendo assim avaliar o progresso do treinamento. Como metodologia, adotou-se a revisão bibliográfica sistemática e exploratória. Foram encontrados 65 artigos relacionados que foram publicados de 203 a 2021, todos selecionados a partir do banco de dados do PubMed e Google Acadêmico, usando os descritores: Elderly (idosos), elastic band (banda elástica), resistance training (treinamento de resistido) para selecionar 9 artigos para serem analisados neste estudo. Analisaram-se artigos focados em treinamento resistido com faixa elástica que são utilizados em idosos, que podem promover diferentes vantagens significativas quanto a melhora as capacidades físicas de idosos. Portanto, este tipo de treinamento pode ser facilmente adotado a vida diária dos idosos, assim chegando à conclusão de que o estudo mostra que o exercício com faixa de resistência é uma alternativa viável para o desenvolvimento de um programa de treinamento de resistência em idosos. Obtendo resultados significantes em proposta ao treinamento resistido.

Acute Effects of Back Squat Combined with Different Elastic Band Resistance on Vertical Jump Performance in Collegiate Basketball Players

Article

Sep 2023
J SPORT SCI MED

The purpose of this study was to compare the acute effects of back squat exercise with or without elastic band on countermovement jump performance. Thirteen collegiate male basketball players (age: 20.5 ± 0.9 years; height: 188.5 ± 8.5 cm; body mass: 82.8 ± 12.9 kg) completed 5 familiarization and 4 experimental sessions separated by at least 48 hours. In the experimental sessions, the order of the conditions was randomized so that the participants performed 1 set of 3 repetitions of barbell back squat at 85% of their one-repetition maximum (1-RM), 1 set of 3 repetitions of back squat at 85% 1-RM with 20% variable resistance training (VRT), 30%VRT, or 40%VRT of the total load coming from the elastic band. Countermovement jump performance was assessed before (baseline), 30 seconds, 3 minutes, 6 minutes, and 9 minutes following each condition. Jump height, rate of force development, peak power, and vastus lateralis, vastus medialis, and medial gastrocnemius electromyography data were collected. Compared with the baseline, 30%VRT significantly improved jump height at 3 minutes post-exercise by 1.3 cm (P < 0.001) and 6 minutes post-exercise by 1.2 cm (P = 0.005); 40%VRT significantly improved jump height from 30 seconds up to the 9th minute (1.2 to 1.9 cm, P ≤ 0.036). The superior jump height was also accompanied by improved kinetic and electromyography data. No significant changes were observed in the barbell back squat and 20%VRT conditions. In conclusion, back squat at 85% 1-RM with 40% elastic band resistance led to superior vertical jump performance with an optimal time window of 3 minutes.

Acute Effects of Back Squat Combined with Different Elastic Band Resistance on Vertical Jump Performance in Collegiate Basketball Players

Article

Full-text available

Aug 2023
J SPORT SCI MED

The purpose of this study was to compare the acute effects of back squat exercise with or without elastic band on countermovement jump performance. Thirteen collegiate male basketball players (age: 20.5 ± 0.9 years; height: 188.5 ± 8.5 cm; body mass: 82.8 ± 12.9 kg) completed 5 familiarization and 4 experimental sessions separated by at least 48 hours. In the experimental sessions, the order of the conditions was randomized so that the participants performed 1 set of 3 repetitions of barbell back squat at 85% of their one-repetition maximum (1-RM), 1 set of 3 repetitions of back squat at 85% 1-RM with 20% variable resistance training (VRT), 30%VRT, or 40%VRT of the total load coming from the elastic band. Countermovement jump performance was assessed before (baseline), 30 seconds, 3 minutes, 6 minutes, and 9 minutes following each condition. Jump height, rate of force development, peak power, and vastus lateralis, vastus medialis, and medial gas-trocnemius electromyography data were collected. Compared with the baseline, 30%VRT significantly improved jump height at 3 minutes post-exercise by 1.3 cm (P < 0.001) and 6 minutes post-exercise by 1.2 cm (P = 0.005); 40%VRT significantly improved jump height from 30 seconds up to the 9th minute (1.2 to 1.9 cm, P ≤ 0.036). The superior jump height was also accompanied by improved kinetic and electromyography data. No significant changes were observed in the barbell back squat and 20%VRT conditions. In conclusion, back squat at 85% 1-RM with 40% elastic band resistance led to superior vertical jump performance with an optimal time window of 3 minutes.

High-velocity power training has similar effects to traditional resistance training for functional performance in older adults: a systematic review

Article

Full-text available

Jun 2023

Questions: What is the effect of high-velocity power training (HVPT) compared with traditional resistance training (TRT) on functional performance in older adults? What is the quality of intervention reporting for the relevant literature? Design: Systematic review and meta-analysis of randomised controlled trials. Participants: Older adults (aged > 60 years), regardless of health status, baseline functional capacity or residential status. Interventions: High-velocity power training with the intent to perform the concentric phase as quickly as possible compared with traditional moderate-velocity resistance training performed with a concentric phase of ≥ 2 seconds. Outcome measures: Short Physical Performance Battery (SPPB), Timed Up and Go test (TUG), five times sit-to-stand test (5-STS), 30-second sit-to-stand test (30-STS), gait speed tests, static or dynamic balance tests, stair climb tests and walking tests for distance. The quality of intervention reporting was assessed with the Consensus on Exercise Reporting Template (CERT) score. Results: Nineteen trials with 1,055 participants were included in the meta-analysis. Compared with TRT, HVPT had a weak-to-moderate effect on change from baseline scores for the SPPB (SMD 0.27, 95% CI 0.02 to 0.53; low-quality evidence) and TUG (SMD 0.35, 95% CI 0.06 to 0.63; low-quality evidence). The effect of HVPT relative to TRT for other outcomes remained very uncertain. The average CERT score across all trials was 53%, with two trials rated high quality and four rated moderate quality. Conclusion: HVPT had similar effects to TRT for functional performance in older adults, but there is considerable uncertainty in most estimates. HVPT had better effects on the SPPB and TUG, but it is unclear whether the benefit is large enough to be clinically worthwhile.

Resistance Training Guidelines for Active Females Throughout the Lifespan, from Childhood to Elderly

Chapter

Feb 2023

Resistance training (RT) configures a specialized method of training that involves the progressive use of a wide range of resistive loads, different rate of muscle activation or movement velocities, and a variety of training modalities. RT is currently considered essential in athletic preparation. It is a key component for optimizing growth and maturation in children, promoting health and quality of life in the elderly, or to attenuate the incidence of injuries in physically active populations. Qualified professionals are necessary to design individualized RT programs for athletes from varying disciplines with very specific performance outcomes. The professional must consider specific needs for all ages, not only the athletic population, making the necessary adaptation to meet their level of ability and desired outcomes. Effective training stimuli should help increase performance and avoid overtraining. This is accomplished by manipulating physiological, neurological, and biomechanical-related variables. There is hard science behind the importance of menstrual cycle-based periodization, and—although research in this area is scarce—results suggest that designing training programs integrating the menstrual cycle hormonal fluctuation or the ingestion of triphasic contraceptives might be of relevance to optimize performance in premenopausal women.

Effects of Free-weight with and without Elastic Band Tension on Upper-Body Strength and Muscular Endurance: A Randomized Parallel Trial

Article

Full-text available

Jul 2022

Yonathan Smoak

Purpose: This study aimed to compare the effects of free-weight resistance with and without elastic band (EB) tension on upper-body maximal strength and strength endurance during bench press (BP) exercise. Methods: Twenty-six trained males (age: 26 ± 2.4 years; body mass: 73 ± 7.6 kg; stature: 172 ± 5.8 cm) were randomly assigned to two groups, CON (n = 13) and EXP (n = 13). BP sessions were performed twice weekly over 12 weeks. Both groups followed the same training program except that the EXP group executed BP with 30% of the prescribed load originating from the use of EB. BP one repetition maximum (1RM) and the maximum number of repetitions (MNR) for muscular fatigue were tested before and after the intervention. Results: Analysis of covariance with the pretest value as the covariate revealed that both the CON and EXP groups demonstrated improvements in maximal strength and muscular endurance. However, the EXP group exhibited significantly greater improvements in 1RM (14% vs. 12%) and MNR (27% vs. 7%). Conclusion: A combination of free-weight and elastic bands may provide a greater training stimulus than free-weight resistance alone to improve upper-body strength and muscular endurance in trained adult men.

A Comparison of Electromyographic Inter-Limb Asymmetry During a Standard Versus a Sling Shot Assisted Bench Press Exercise

Article

Full-text available

Sep 2022
J HUM KINET

The objective of this study was to compare peak surface electromyography (sEMG) activity of selected muscles along with inter-limb asymmetries between a control (CONT) and a Sling shot assisted (SS) bench press exercise. Ten resistance-trained males with at least three-year experience in resistance training (22.2 ± 1.9 years, 88.7 ± 11.2 kg, 179.5 ± 4.1 cm, bench press one-repetition maximum (1RM) = 127.25 ± 25.86 kg) performed the flat bench press exercise under two conditions at selected loads (85% and 100% of 1RM assessed without the SS). Peak sEMG amplitude of triceps brachii, pectoralis major, and anterior deltoid was recorded for the dominant and the non-dominant side of the body during each attempt. The comparison between the dominant and the non-dominant side was carried out using the limb symmetry index (LSI(%) = (2*(XR-XL)/(XR + XL))*100%) where XR = values of the right side and XL = values of the left side. There was a main effect of condition (p = 0.004; η2 = 0.64) and the load (p = 0.004; η2 = 0.63) for the triceps brachii LSI in parallel with a main effect of condition (p = 0.003; η2 = 0.42) for the anterior deltoid LSI. Post hoc analysis for the main effect of condition showed significant differences in the LSI between the CONT and SS conditions for the triceps brachii (p = 0.003; 1.10 vs.-8.78) as well as for the anterior deltoid muscles (p = 0.03; 12.91 vs. 9.23). The results indicate that the assistance of the Sling shot significantly affects the sEMG activity pattern on both the dominant and non-dominant sides of the body while influencing inter-limb asymmetries.

The Acute Effects of Attaching Chains to the Barbell on Kinematics and Muscle Activation in Bench Press in Resistance-Trained Men

Article

Full-text available

May 2022

The aim of the study was to investigate the acute effects of attaching chains on barbell kinematics and muscle activation in the bench press. Twelve resistance-trained men (height: 1.79 ± 0.05 m, weight: 84.3 ± 13.5 kg, one repetition maximum (1-RM) bench press of 105 ± 17.1 kg) lifted three repetitions of bench press in three conditions: (1) conventional bench press at 85% of 1-RM and bench press with chains that were (2) top-matched and (3) bottom-matched with the resistance from the conventional resistance lift. Barbell kinematics and the muscle activity of eight muscles were measured at different heights during lowering and lifting in the three conditions of the bench press. The main findings were that barbell kinematics were altered using the chains, especially the 85% bottom-matched condition that resulted in lower peak velocities and longer lifting times compared with the conventional 85% condition (p ≤ 0.043). However, muscle activity was mainly only affected during the lowering phase. Based upon the findings, it was concluded that using chains during the bench press alters barbell kinematics, especially when the resistance is matched in the bottom position. Furthermore, muscle activation was only altered during the lowering phase when adding chains to the barbell.

A Review of Striking Force in Full-Contact Combat Sport Athletes: Effects of Different Types of Strength and Conditioning Training and Practical Recommendations

Article

Full-text available

Feb 2022

To succeed in full contact combat sports like mixed martial arts, tae kwon do, and boxing, athletes must deliver a greater number of damaging strikes than they receive. Producing knockdowns, rendering unconsciousness, and scoring points can be accomplished through the application of high magnitudes of striking forces. There is evidence that striking forces can be enhanced through either nonspecific or specific strength and conditioning methods or a combination thereof. To better assist practitioners working with combat sport athletes, this article reviews current empirical evidence on how combat sport athletes respond to different methods of resistance training and offers practical recommendations for implementing nonspecific and specific exercises.

Modulus of Elasticity of Elastic Tubes Used in Neuromuscular Rehabilitation Programs

Article

Full-text available

Sep 2021

Context: The elastic tubes have been used for clinical rehabilitation programs in which exercises are performed with submaximal intensities due to the difficulty in the measure the applied force. The authors aimed to quantify the elastic constant of elastic tubes used in neuromuscular rehabilitation programs predicting the force related to elastic tube elongation. A force test was performed by stretching the elastic tubes to determine the relationship between force and elongation. Eight elastic tubes with progressive levels of resistance represented by colors (yellow, red, blue, gray, black, grape, purple, and gold-low to higher resistance) were used. Design: Experimental. Methods: The test and retest were compared using the paired t test. The agreement and reliability between the test versus retest of pooled means colors were analyzed by plotting the Bland-Altman graph and intraclass correlation coefficient and the coefficient of variation. Pearson correlation was used to verify the validity between measurements. Results: The force values generated from the elastic tube elongation increase according to the color and thickness of elastic tubes with a strong and significant association between them (P < .0001). The elastic constant measurements were similar and presented high intraclass correlation coefficient values, low coefficient of variation values, and were reproducible (P < .0001). Conclusions: The force could be quantified according to elastic tube length variation by the linear regression equation with reproducibility. It gives greater measurement precision and better training load control when using elastic tubes in strength training programs.

Acute Effects of Elastic Bands as Resistance or Assistance on EMG, Kinetics, and Kinematics During Deadlift in Resistance-Trained Men

Article

Full-text available

Oct 2020

The aim of the study was to compare neuromuscular activation, kinetics and kinematics in three variations of the deadlift: (1) free weights, (2) free weights with elastic bands as resistance (bands anchored to the ground) and (3) free weights with elastic bands as assistance (bands attached above the bar). Sixteen resistance-trained men performed one repetition of the three variations as fast as possible using a 2-repetition maximum load in randomized and counterbalanced order. Muscle activation (gluteus maximus, semitendinosus, biceps femoris, erector spinae, vastus lateralis, and vastus medialis), kinematics (average-, peak-, and time to peak velocity), and kinetics (average-, peak,-and time to peak force) were measured during the ascending movement. Resisted and assisted deadlifts led to higher average and peak force outputs (p < 0.001–0.037, ES = 0.29–0.58), and time to peak velocity was shorter when compared to the free weights deadlift (p = 0.005–0.010, ES = 0.83–1.01). However, peak force was achieved faster when using free weights (p < 0.001, ES = 1.58–2.10) and assisted deadlifts had a lower peak velocity compared to resisted and free weights deadlift (p = 0.004–0.046, ES = 0.43–0.60). There were no significant differences in muscle activation between the different conditions (p = 0.082–1.000). In conclusion, the assisted and resisted deadlift produced higher force when compared to free weights. However, free weight and resisted deadlift seem more favorable for the barbell velocity. These findings are of importance for athletes and coaches which should select exercise depending on the goal of the session.

Análisis cinético y cinemático de un press de banca a diferentes intensidades de carga.

Article

Full-text available

Aug 2020

Resumen. El press de banca (PB) es uno de ejercicios con más tradición en las ciencias del deporte. Su estudio ha sido abordado desde diferentes perspectivas, principalmente analizando los efectos de variantes técnicas orientadas a mejorar la programación del entrenamiento en diferentes deportes y poblaciones. La repetición máxima ha sido utilizada como referencia para cuantificar la carga en diversidad de estudios. Sin embargo, es necesario conocer cómo ajustar las intensidades de entrenamiento para poder programar con mayor precisión. El objetivo de la presente investigación fue analizar el comportamiento de las variables cinéticas, cinemáticas y psicológicas a distintos porcentajes de la 1RM (repetición máxima) del PB. Treinta estudiantes universitarios sanos formaron parte de la muestra experimental (Edad 23 ± 0,45 años; talla 181,13 ± 2,25 cm; peso 78,25 ± 4,81 Kg; porcentaje muscular 52,10 ± 0,30%, porcentaje graso 12,05 ± 0,59%; IMC 24, 12 ± 0,84). Los participantes realizaron una sesión de familiarización con la técnica del PB y realizaron un test incremental para la obtención de la 1RM. Después de 7 días volvieron a realizar el mismo protocolo, pero a diferentes intensidades de la 1RM (20%, 40%, 60%, 80% y 100%). Los datos obtenidos aportaron información descriptiva del comportamiento de las variables analizadas al aumentar la carga en sujetos entrenados. La presente investigación podría sugerir variaciones en las cargas de trabajo previstas y predecir posibles adaptaciones dentro de la programación del trabajo de fuerza. Palabras clave: Repetición máxima, fuerza, velocidad, potencia, pres de banca, percepción del esfuerzo Abstract. Bench press exercise is one of the most popular exercises in sports science. It has been studied from different approaches, mostly analyzing the effects of technical variations in order to improve training schedule on different sports and populations. The one repetition maximum has been used as a reference to quantify the load in diverse studies. However, knowing how to adjust training intensities is necessary in order to schedule training accurately. The objective of the present study was to analyze the response of kinematic, kinetic and psychological variables at different percentages of 1RM. The study sample was comprised of thirty healthy university students (Age 23 ± 0.45 years; height 181.13 ± 2.25 cm; weight 78.25 ± 4.81 Kg; muscle percentage 52.10 ± 0.30%, fat percentage 12.05 ± 0.59%; BMI 24, 12 ± 0.84). The participants attended a familiarization session with the bench press technique and performed an incremental test to obtain the 1RM. They returned to carry out the same protocol seven days after, but different intensities of the 1RM were accomplished (20%, 40%, 60%, 80% and 100%). The results obtained provided descriptive data about the behaviour of the analyzed variables by increasing the load on trained subjects. The present research could suggest variations in the expected workloads and predict possible adaptations within the force work schedule.

In-season in-field variable resistance training: effects on strength, power, and anthropometry of junior soccer players

Article

Feb 2020

BACKGROUND: Soccer players’ leg muscular strength and power have been shown to be significant due to their association with soccer-specific performance including jumps, sprints, tackles and kicks. The aim of this study, therefore, was to examine the effects of an in-season in- field variable resistance training (VRT) program on strength, power, and anthropometry of junior soccer players. METHODS: A team of male soccer players were randomly divided into Experimental (n=10) and Control groups (n=10). The Control group performed 8 weeks of soccer training alone. The Experimental group performed squat VRT using chains in addition to soccer training. Measures before and after training included one repetition maximum (1RM) of squat, countermovement jump (CMJ), and anthropometric estimation of thigh muscle cross sectional area (CSA). RESULTS: The VRT induced large improvements in absolute (34.45%; p=0.001; Cohen’s d=1.78) and relative strength to thigh muscle CSA (21.53%; p=0.002; Cohen’s d=1.04). Similarly, there were large (18.07%, p=0.007; Cohen’s d=1.5) increases in jump height and medium gains in absolute peak power output (16.13%; p=0.009; Cohen’s d=0.34) and relative peak power output to thigh muscle CSA (9.6%; p=0.002; Cohen’s d=0.31). Further, there was a medium increase (5.9%, p=0.03; Cohen’s d=0.36) in thigh muscle CSA. No significant changes were observed in the Control group. CONCLUSIONS: In-season in-field biweekly squat VRT enhanced strength and power measures in junior soccer players. KEY WORDS: Resistance training; Lower extremity; Muscle strength; Power; Anthropometry; Soccer

Frequência semanal no treinamento de força

Chapter

Full-text available

Dec 2019

Variáveis práticas do treinamento de força

Chapter

Full-text available

Dec 2019

The Landmine Squat Exercise

Article

Jul 2024

The comparison of the effect of variable and constant resistance training on the salivary testosterone, cortisol and growth hormone in trained men

Article

Full-text available

Feb 2023

Background and Purpose: Variable resistance training (VRT) is a type of resistance training that helps to improve muscle strength and function through extra resistance such as elastic bands and chains. The comparison of the effect of constant resistance training (CRT) versus VRT on hormonal response has not been fully studied. So, this study investigated the acute and chronic effects of VRT versus CRT on the salivary concentration of testosterone, growth hormone, and cortisol in trained men. Materials and Methods: 30 young resistance-trained men were recruited for this study and were randomly assigned to three groups including VRT, CRT, and control. Both training groups performed an exercise protocol with an intensity of 65 to 85% of 1RM for 10 weeks and 3 sets (three sessions per week). The training included the main upper and lower extremity exercises and the rest period between the sets and exercises was 1 and 2-3 minutes respectively. In addition, the VRT group used 7.5 kg chains as an external variable resistance. Oral saliva samples were collected before and after the first session (acute response) and the last session (chronic response) and then analyzed by ELISA method. Inter-group changes were analyzed by repeated measures analysis of variance and Bonferroni's post hoc test. The significance level was also considered equal to P ≤ 0.05. Results: a significant group×time interaction was observed only for the acute response of salivary testoster-one (P = 0.003). So, a significant increase was observed in the salivary of testosterone in the VRT compared to CRT (P = 0.001) and control (P = 0.003), although no significant differences were observed for cortisol (P=0.64), growth hormone (P = 0.52) and testosterone to growth hormone (P = 0.49). Also, no significant group×time interaction was observed for testosterone (P = 0.377), cortisol (P=0.57), testosterone to cortisol ratio (P = 0.91), and growth hormone (P = 0.200) in chronic response (P > 0.05). Conclusion: The results showed that a session of VRT caused a significant increase in testosterone hormone immediately after exercise, but 10 weeks of VRT or CRT had no significant effect on the levels of testos-terone, cortisol, and growth. It seems that if VRT is performed with higher intensity or volume, additional hormonal responses will occur as a result of exercise, and therefore the effectiveness of the exercise will promote.

A Cable-Driven Portable Fitness Chair with Programmable Resistance for Effective Muscle Training

Conference Paper

Jul 2023

Seven-Week Accommodating Resistance Training Improves Wingate Peak Power But Not Muscular Strength or Endurance in Strength-Trained Females

Article

Apr 2023
J STRENGTH COND RES

Parten, AL, Barker, GA, O'Neal, EK, and Waldman, HS. 7-week accommodating resistance training improves Wingate peak power but not muscular strength or endurance in strength-trained females. J Strength Cond Res XX(X): 000-000, 2022-Accommodating resistance (AR) is a training technique that includes attaching elastic bands or chains to a loaded barbell to alter the resistance profile throughout the barbell movement. This study was the first to quantify the effects of AR versus a traditional resistance (TR) training program on changes in strength and power profiles in a trained female cohort. Resistance-trained (training history: 2.4 ± 1.4 years) females (age: 22.1 ± 3.0 years) completed baseline and postintervention tasks which included 1 repetition maximum (1RM) testing in the back squat (BS) and bench press (BP), a repetitions to failure in the BP (60% of 1RM), and 1 30-s Wingate test. After baseline testing, subjects were stratified (based on relative strength) into either the AR (n = 9) or TR (n = 10) group and then completed a supervised, 7-week training intervention. Both groups improved their 1RM in both lifts, but no statistical differences were found between groups in 1RM for BS, BP, or BP to failure (p > 0.05). However, the AR group increased Wingate peak power (837 ± 221 to 901 ± 215 W; p = 0.04), whereas TR (868 ± 244 to 8,343 ± 182 W; p = 0.47) did not. This study supports AR with lighter relative barbell load incurs similar strength adaptations as TR. For coaches training athletes concerned with power, AR may be advantageous for improving rate of force development as demonstrated by large increases in peak Wingate power.

Effect of theraband exercises on muscle strength and motor development of individuals with moderate intellectual disability

Article

Mar 2023
SOMATOSENS MOT RES

Individuals with Moderate Intellectual Disability (MID) have lower levels of physical activity than typically developing peers. Considering the positive effects of physical activity on health, it is vital to identify effective exercise interventions for individuals with MID in everyday environments. The aim of our study was to examine the effects of theraband exercises on muscle strength and motor development of individuals with MID. A total of 16 individuals with MID were included in the study. Participants were divided into experimental and control group by random sampling method. Theraband exercise training was applied on the experimental group (60 min/2 days/10 weeks), but no exercise program was applied on the control group. When post-test results were evaluated between the groups, there was significant difference in favour of experimental group in terms of muscle strength and Bruininks-Oseretsky Test of Motor Proficiency- Second Version-Short Form (BOT-2-SF) total motor performance parameters (p < 0.05). The difference between pre-test and post-test values of total motor performance parameters of muscle strength and BOT-2 SF in experimental group were significant (p < 0.05). As a result, it was found that 10-week (60 min/2 days/10 weeks) theraband exercise positively affected the muscle strength and motor development of individuals with MID.

The Wide Grip Tubing Row Exercise

Article

Mar 2023

Peter Ronai

Which ROMs Lead to Rome? A Systematic Review of the Effects of Range of Motion on Muscle Hypertrophy

Article

Full-text available

Sep 2022
J STRENGTH COND RES

Resistance exercise range of motion (ROM) influences muscular adaptations. However, there are no consistent practical guidelines about the optimal ROM for maximizing muscle hypertrophy. The objective of the present paper was to systematically review the literature for studies that compared the effects of full ROM (fROM) and partial ROM (pROM) on muscle hypertrophy. PubMed/MEDLINE, Scopus, and Web of Science databases were searched to identify articles from the earliest record up to and including April 2022. We calculated the effect size (ES) scores of the variables of interest. Eleven studies were included in the review. fROM and pROM performed in the initial part of the ROM elicited greater muscle hypertrophy of the rectus femoris, vastus lateralis, biceps brachii and brachialis distal sites (between-groups ES: 0.20–0.90) than pROM performed in the final part of the ROM. fROM elicited greater muscle growth on the gluteus maximus and adductors than pROM in the final part of the ROM (between-groups ES: 0.24–0.25). Initial pROM produced more favorable proximal rectus femoris hypertrophy than fROM (between-group ES: 0.35–0.38). pROM in the middle part of the ROM elicited greater triceps brachii hypertrophy than fROM (between-groups ES: 1.21). In conclusion, evidence suggests that when training at a longer muscle length—through either a pROM or fROM—some muscles, such as the quadriceps femoris, biceps brachii and triceps brachii tend to experience optimal growth. Thus, the use pROM in the initial part of the excursion in combination with fROM training should be considered when prescribing hypertrophy-oriented resistance training programs.

Acute effects of variable resistance training on force, velocity, and power measures: a systematic review and meta-analysis

Article

Full-text available

Aug 2022

Objective: Acute effects of variable resistance training (VRT) and constant resistance training (CRT) on neuromuscular performance are still equivocal. We aimed to determine the differences between VRT and CRT in terms of force, velocity, and power outcomes. Methods: We searched PubMed, Web of Science, and SPORTDiscus electronic databases for articles until June 2021. Crossover design studies comparing force, velocity, and power outcomes while performing VRT and CRT were included. Two reviewers independently applied the modified version of the Cochrane Collaboration's tool to assess the risk of bias. A three-level random effects meta-analyses and meta-regressions were used to compute standardized mean differences (SMDs) and 95% confidence intervals. Results: We included 16 studies with 207 participants in the quantitative synthesis. Based on the pooled results, VRT generated greater mean velocity (SMD = 0.675; moderate Grading of Recommendations Assessment, Development and Evaluation (GRADE) quality evidence) and mean power (SMD = 1.022; low) than CRT. Subgroup analyses revealed that VRT considerably increased the mean velocity (SMD = 0.903; moderate) and mean power (SMD = 1.456; moderate) in the equated loading scheme and the mean velocity (SMD = 0.712; low) in the CRT higher loading scheme. However, VRT marginally significantly reduced peak velocity (SMD = -0.481; low) in the VRT higher loading scheme. Based on the meta-regression analysis, it was found that mean power (p = 0.014-0.043) was positively moderated by the contribution of variable resistance and peak velocity (p = 0.018) and peak power (p = 0.001-0.004) and RFD (p = 0.003) were positively moderated by variable resistance equipment, favoring elastic bands. Conclusions: VRT provides practitioners with the means of emphasizing specific force, velocity, and power outcomes. Different strategies should be considered in context of an individual's needs. Systematic review registration: PROSPERO CRD42021259205.

THE EFFECTS OF INSPIRATORY MUSCLE TRAINING VERSUS CALF MUSCLE TRAINING ON QUALITY OF LIFE, PAIN, VENOUS FUNCTION AND ACTIVITY IN PATIENTS WITH CHRONIC VENOUS INSUFFICIENCY

Article

Jun 2022

Objective The aim of this study was to evaluate the effect of inspiratory muscle training(IMT) and calf muscle exercise training(ETC) in addition to compression therapy(CT) on quality of life, venous refilling time, disease severity, pain, edema, range of motion, muscle strength and functionality in patients with chronic venous insufficiency (CVI) compared to compression treatment alone. Methods Thirty-two participants diagnosed with CVI were randomly divided into three groups. IMT in addition to compression therapy, Group 1, exercise training for the calf muscle in addition to compression therapy, Group 2, and compression therapy alone, Group 3. All the patients were assessed with the Chronic Venous Insufficiency Quality of Life Questionnaire-20, Nottingham Health Profile, photoplethysmography, venous clinical severity score, visual analog scale, intraoral pressure measurements, dynamometer, digital goniometer, 6-minute walk test and lower extremity functional scale. Results After treatment, Group 2 improved more than groups 1 and 3 in terms of quality of life, venous refilling time, pain, edema, range of motion, muscle strength and functionality scores; Group 1 improved more than groups 2 and 3 in terms of disease severity, inspiratory and expiratory muscle strength values(p<0.05). Only physical mobility and right leg venous refilling time increased in group 3(p<0.05). Conclusions IMT and ETC improve venous function in both legs in patients with CVI while CT alone improves venous function only in the right leg of patients with CVI.

Factors Modulating the Priming Response to Resistance and Stretch-Shortening Cycle Exercise Stimuli

Article

Full-text available

May 2022

“Priming exercises” are gaining popularity as a precompetition strategy to improve subsequent performance. Although priming exercise has been shown to improve various neuromuscular performance measures within 48 hours, a number of studies have also found no change or significant decreases in performance following priming interventions. Inconsistencies in findings are likely due to the many different variables used in the research. In addition, evidence suggests that the potential performance response following a priming stimulus is likely to be influenced by individual characteristics. Therefore, the purpose of this review is to examine the available evidence and identify those variables that most strongly determine whether priming stimuli involving resistance and stretch-shortening cycle exercise tasks are likely to improve performance within 48 hours of that stimulus. In addition to making recommendations based on the evidence to date, directions for future research are also identified.

Effects of Corrective Exercise Protocol Utilizing A TheraBand on Muscle Activity During Running in Individuals With Genu Valgum

Article

May 2022

Background and Aims: Genu valgum is among the most common lower limb malalignments impacting people’s performance. The present study’s objective was to investigate the effects of a corrective exercise protocol utilizing TheraBand on muscle activity during running in individuals with genu valgum. Methods: The present study was a semi-experimental and laboratory study, in which 24 male students (20-30 years old) were randomly divided into the control and experimental groups. Corrective exercises were performed on the experimental group for eight weeks using a thera-band. The electrical activity of selected muscles was recorded via the electromyography system. Statistical analysis was conducted utilizing measures, such as repeated measures Analysis of Variance (ANOVA) (significance level: 0.05). Results: The findings revealed a significant decrease (69.98%) in bicep femoris muscular activity during the stance phase of running posttest compared to pretest (d=1.88, P=0.002). Moreover, a significant decrease (33.77%) in the electrical activity of the semitendinosus muscle was detected in the posttest compared to the pretest (d=0.86, P=0.024). The electrical activity of other muscles did not indicate any significant differences in the posttest compared to the pretest (P>0.05). Conclusion: Decline in bicep femoris muscle activity in individuals with genu valgus indicates the positive impact of rehabilitation via TheraBand as well as enhanced performance in their daily activities.

Effect of Corrective Exercise on Lower Limb Muscles' Co-contraction in Males with Genu Valgum during Walking: A Clinical Trial Study

Article

Mar 2022

Background and Objective: Genu valgum is one of the most common lower limb malformations that affects on walking mechanics. This study was done to evaluate the effect of corrective exercise with Thera-band on the lower limb muscles’ cocontraction in males with genu valgum during walking. Methods: In this clinical trial study, 24 male students with genu valgus with age range of 20-30 years were randomly divided into two control (n=12) and intervention (n=12) groups. Using the caliper, the intensity of the genu valgum was measured by assessing the distance between the medial malleolus of the subjects. Corrective exercises were performed for 8 weeks using Thera-band in interventional group. The electrical activity of selected muscles was recorded by electromyography system (biometrics ltd, UK). Results: In the interventional group, the knee joint flexor/extensor directed co-contraction was increased significantly during the heel contact phase in the post-test than that in the pre-test (P<0.05). There was also a significant increase in knee joint general co-contraction during heel off phase (P<0.05). In the interventional group, directed co-contraction of vastus lateralis /vastus medialis muscles during the swing phase was significantly increased during the post-test in compared to the pre-test (P<0.05). During post-test, knee joint flexor/extensor directed co-contraction during the heel, knee joint general co-contraction during heel off phase and directed co-contraction of vastus lateralis / vastus medialis muscles during the swing phase were more in the interventional group in compared to control group (P<0.05). Conclusion: The increase of general co-contraction in the knee joint during the heel off phase reflects an improvement in activity of the knee support muscles after corrective exercises and increases balance and stability. There was also an increase in the knee joint flexor / extensor direction co-contraction, which increase the distribution of the load and pressure between the femur and tibia in the knee joint.

The Effects of a Corrective Exercise Protocol using a Thera-Band on Muscle Activity in Individuals with Genu Valgum during Running

Article

Full-text available

Mar 2022

ackground and Aim: Genu Valgum is one of the most common lower limb malalignments that affects people's performance. The purpose of the present study was to investigate the effects of a corrective exercise protocol using a Theraband on muscle activity in individuals with genu valgum during running. Materials and Methods: The present study was a semi-experimental and laboratory study. 24 male students (20-30 years old) were randomly divided into control and experimental groups. Corrective exercises were performed for 8 weeks using Theraband on the experimental group. The electrical activity of selected muscles was recorded by electromyography system Statistical analysis was performed using repeated measures ANOVA test at the significant level of 0.05. Results: The results of the present study showed a significant decrease in biceps femoris muscular activity during stance phase of running by 69.98% in post-test compared to the pre-test (d=1.88, P=0.002). Also, the findings of the study showed a significant decrease in the electrical activity of the semitendinosus muscle during the post-test compared to the pre-test by 33.77% (d=0.86, P=0.024). The electrical activity of other muscles did not show any significant difference during post-test compared to pre-test (P>0.05). Conclusion: Decreased of biceps femoris muscle activity in individuals with genu valgus indicates a positive effect of rehabilitation using Theraband, and improving of performance in their daily activities.

Does Varying Resistance Exercises Promote Superior Muscle Hypertrophy and Strength Gains? A Systematic Review

Article

Full-text available

Jan 2022
J STRENGTH COND RES

Fitness professionals routinely employ a variety of resistance training exercises in program design as a strategy to enhance muscular adaptations. However, it remains uncertain whether such an approach offers advantages over a fixed-exercise selection. The objective of this paper was to review the effects of exercise variation on muscle hypertrophy and strength. A search of literature was conducted using PubMed/MEDLINE, Scopus, and Web of Science databases. Eight studies were identified as meeting inclusion criteria. The combined total sample of the studies was n = 241, comprising all young men. The methodological quality of included studies was considered "good" and "excellent" based on the PEDro Scale. The available studies indicate that varying exercise selection can influence muscle hypertrophy and strength gains. Some degree of systematic variation appears to enhance regional hypertrophic adaptations, and maximize dynamic strength, whereas excessive, random variation may compromise muscular gains. We conclude that exercise variation should be approached systematically with a focus on applied anatomical and biomechanical constructs; on the contrary, employing different exercises that provide a redundant stimulus, as well as excessive rotation of different exercises (i.e., high frequency of change), may actually hinder muscular adaptations.

Performance Responses of Child Footballers to Thera-Band Exercise

Article

Full-text available

Dec 2021

Bu çalışmanın amacı, futbolcu çocuklara uygulanan 8 haftalık terabant egzersizlerine performans yanıtlarının incelenmesidir. Çalışmanın örneklemini Bingöl ilinde aktif olarak futbol oynayan 14 çocuk gönüllü olarak oluşturmuştur. Çalışma 1 deney ve 1 kontrol grubundan oluşmaktadır. Deney grubuna haftalık 7 saat ve üzeri (4-5 birim) olmak üzere 8 hafta boyunca terabant egzersizi ve futbol antrenmanı (n=7, yaş: 14,00±0,81 yıl, boy uzunluğu: 162,15±0,07 cm, vücut ağırlığı: 47,74±4,40 kg ), kontrol grubuna ise (n=7, yaş: 15,14±0,82 yıl, boy uzunluğu: 166±0,06 cm, vücut ağırlığı: 49,02±3,18 kg ) 8 hafta boyunca sadece futbol antrenmanı uygulanmıştır. Çalışmaya katılan futbolcu çocuklar 2 gruba randomize atanmıştır. Çocukların performans farklarını incelemek amacıyla her iki gruba da ön-test ve son-test olmak üzere antropometrik ölçümler, mekik, esneklik, 20 metre sürat, durarak uzun atlama, arrowhead çeviklik ve dinamik denge (Y testi) testleri uygulanmıştır. Gruplar arası, grup içi ve antrenmanın etkisine ilişkin analizler tekrarlı ölçümlerde çok yönlü varyans analizi (MANOVA) ile yapılmıştır. Anlamlı olan değerlerde Post Hoc karşılaştırmaları Bonferroni Testi ile belirlenmiştir. Çalışma sonucunda grupların performans sonuçları incelendiğinde deney grubunun grup içi ön –son test sonucunda durarak uzun atlama, mekik, esneklik, arrowhead çeviklik ve 20 m sürat değerlerinde p

Kinetic and Kinematic Analysis for Exercise Design: A Practical Approach

Chapter

Jan 2022

Víctor Cuadrado

This chapter introduces the importance to study movement in the sports context, where human performance focuses on the continuous optimization of the physical condition of athletes in specific situations, which often require to be performed at high intensities. To optimize these actions, it is necessary to prioritize strength training, focused on improving useful strength, understood as the application of strength under specific time and velocity conditions per training to competitive exercise (issues reflected in force–velocity and force–time curves). To carry out from practice, it is necessary to monitor, quantify, adapt and prescribe strength training to understand the existing relationship between the external load proposed for the subject and its organic consequences to achieve the adaptations sought and thus optimize performance. To achieve this, it is important to measure and control movement from a mechanical perspective. In this sense, in this chapter, an initial analysis of different methods of strength training through kinetics and kinematics will be proposed.

Variable Resistance Training Methods

Chapter

Jan 2022

Fernando Hernández-Abad

Variable resistance training devices have become a widespread tool in strength programs. One of the advantages of using this type of training device is the increase or decrease of the external resistance throughout the range of movement. In addition to the good results obtained by the use of elastic bands and chains, which have become widely popular due to their positive adaptations in the expression of strength, versatility, and ease of use, the use of conical pulleys has been added in recent years. In this chapter, we will describe how to approach training with variable resistance training devices, although they are a very ecological resource within the training process and have a wider range of possibilities than the most commonly used. We will take a journey from a traditional vision to offer a more contemporary vision, based on our personal experience, both in high performance and in the rehabilitation and prevention of sports injuries. In addition, there will be a brief introduction and contextualization of the concepts of dynamic rotational stability and vector diversification, proposals to optimize the use of training resources with variable resistance.

INVESTIGATING THE EFFECT OF 8 WEEKS OF CORRECTIVE EXERCISE WITH AN ELASTIC BAND ON THE FREQUENCY SPECTRUM OF GROUND REACTION FORCES IN YOUNG BOYS WITH GENU VALGUM DURING RUNNING: A RANDOMIZED CLINICAL TRIAL STUDY

Article

Feb 2021

Background & Aims: Increasing the angle of the valgus by making changes to the lower limbs can cause changes in the center of gravity of the body relative to the level of reliance and limit balance control. The aim of this study was to investigate the effects of a corrective exercise course using an elastic band on the frequency spectrum of ground reaction forces in young boys with genu valgum during running. Materials & Methods: The present study was a clinical trial. 24 male students with genu valgum (20- 30 years) were randomly assigned to control and experimental groups. Corrective exercises were performed for 8 weeks using an elastic band for the experimental group. Ground reaction forces were recorded by the Bertec force plate. For statistical analysis, SPSS V21 software and analysis of repeated measure ANOVA were used at a significance level of 0.05. Results: The results of the present study showed a decrease in the median frequency in the anteriorposterior direction of the experimental group during the post-test compared to the pre-test (p = 0.025; d = 3.921). Also, in the experimental group, the frequency band component showed a significant decrease in anterior-posterior direction during the post-test compared to pre-test (p = 0.028; d = 3.843). Conclusion: Due to the reduction in median frequency, it can be concluded that the corrective exercises used were able to reduce the incoming forces in the anterior-posterior direction. With the reduction of the frequency band during corrective exercises, the participation and activity of motor performance have also decreased.

Effect of a Corrective Exercise Program on the Frequency Spectrum of Ground Reaction Force during Drop-Landing in Older Adults with Genu Valgum. Salmand

Article

Full-text available

Apr 2020

Objectives The aim of this study was to evaluate the effects of a corrective exercise protocol on the frequency spectrum of Ground Reaction Force (GRF) in older adults with genu valgum during double-leg drop-landing task. Methods & Materials The is a quasi-experimental study (a registered clinical trial with code: IRCT2016110230657N1). Participants were 26 elderly men with genu valgum (13 in intervention group and 13 in control group). The GRF data were measured by two force plates (Kistler Group, Winterthur, Switzerland). The corrective exercise was performed for 16 weeks, 3 sessions per week. All participants signed a written consent form and the study design was approved by the ethics committee. Those subjects with a history of injury were excluded from the study. The two-way repeated measures ANOVA was used for statistical analysis. Results The mean age of participants in the intervention and control groups were 63.92±2.21 and 64.01±2.62 years, respectively. Based on the ANOVA results, the effect of time factor on the frequency with a power of 99.5% in vertical GRF (P=0.003) and the number of essential harmonics in anterior-posterior direction (P=0.006) was significant in the left leg. The effect of group factor on the 99.5% frequency power (P=0.006) and the number of essential harmonics of vertical GRF (P=0.047) in the left leg was also significant. Furthermore, the interaction effect of group and time on the 99.5% frequency power (P

Training with rubber bands

Article

Full-text available

Dec 2004

The use of bands in strength training may provide more resistance in sport-specific training, but they may also hinder range of motion and muscle growth.

A kinesiological analysis of the tennis service

Article

Full-text available

Oct 1988

David Behm

Surgical tubing for sport and velocity specific training

Article

Full-text available

Aug 1988

David Behm

Resistive Torque Validation of the Nautilus Multi-Biceps Machine

Article

Full-text available

Feb 1999

The validity of the Nautilus Third Generation Multi-Biceps Machine (NBM) was examined against the strength curves of the elbow flexors. The Nautilus machine resistive torque (MRT) values were compared to the maximal human torque capability (HTC) curve generated via isokinetic elbow flexion testing by 10 subjects. Measurements of the MRT and HTC values were made with a Cybex II isokinetic device at 3 different angular velocities. The values were normalized to percent of maximum torque and were graphically illustrated. Analysis of a 2-sample independent t-test showed a significant difference between the HTC and MRT curves in the extreme positions of the range of motion (ROM) (p < 0.05). It was concluded that the resistance of the NBM did not match the strength curves of the elbow flexors throughout the entire ROM.

SPORTS PERFORMANCE SERIES: A kinesiological analysis of the tennis service

Article

Full-text available

Oct 1988

David Behm

Terminology and Measurement in Exercise Performance

Article

Full-text available

Feb 1987

Training and testing in open versus closed kinetic chain

Article

Full-text available

Dec 2003

Optimization of different forms of training and testing in sports and therapy has traditionally been debated by various groups. Especially, the use of so-called open and closed kinetic chain exercises has frequently been a focal point. Scientific studies have indicated that no specific form of exercise and/or training has any particular advantage over the other. This applies to both assessment of efficiency, consideration of compression and shear forces, muscular activity and the extent of co-contractions. Unlike the broadly-applied non-specific and uncritical assessment of open and closed kinetic chain exercises, a specific application using the advantages of both procedures must be considered due to clinical, therapeutic and training-physiological aspects. Specificity refers to the training of either an isolated joint-muscle unit (arthron) or a system (group) of joints and muscles. Considering the original definitions and past misinterpretations, it appears logical to emphasize the role of physiological mecha-nisms operating in each form of training and testing. Therefore, the use of the term: single-joint (SJ) or multi-joint (MJ) training, is recommended since this would best reflect the area of application, according to a recent consensus expressed by EISCSA. Consequently, SJ and MJ exercises should be applied both in isolation and in combination as indicated by the principles of specificity. On the other hand, continuous use of the terms open and closed kinetic chain exercises is confusing, erroneous, leads to polarizing discussions and should hence be relegated to the past.

Biomechanics of Strength and Strength Training

Chapter

Full-text available

Jan 2008

Vladimir M Zatsiorsky

This chapter contains section titled:

Strength training methods and the work of Arthur Jones

Article

Full-text available

Jan 2009

Full-text of this article is available at http://www.asep.org/files/Smith.pdf This paper reviews research evidence relating to the strength training advice offered by Arthur Jones, founder and retired Chairman of Nautilus Sports/Medical Industries and MedX Corporation. Jones advocated that those interested in improving their muscular size, strength, power and/or endurance should perform one set of each exercise to muscular failure (volitional fatigue), train each muscle group no more than once (or, in some cases, twice) per week, perform each exercise in a slow, controlled manner and perform a moderate number of repetitions (for most people, ~8-12). This advice is very different to the strength training guidelines offered by the National Strength and Conditioning Association, the American College of Sports Medicine and most exercise physiology textbooks. However, in contrast to the lack of scientific support for most of the recommendations made by such bodies and in such books, Jones’ training advice is strongly supported by the peer-reviewed scientific literature, a statement that has recently been supported by a review of American College of Sports Medicine resistance training guidelines. Therefore, we strongly recommend Jones’ methods to athletes and coaches, as they are time-efficient and optimally efficacious, and note that, given his considerable contribution to the field of strength training, academic recognition of this contribution is long overdue.

Motor unit physiology: Some unresolved issues

Article

Full-text available

Feb 2001

The purpose of this review was to examine three issues that limit our understanding of motor unit physiology: (1) the range and distribution of the innervation ratios in a muscle; (2) the association between discharge rate and force; and (3) the variation in motor unit activity across contractions that differ in speed and type. We suggest that if more data were available on these issues, the understanding of neuromuscular function would be enhanced substantially, especially with regard to plasticity in the motor neuron pool, adequacy of the neural drive to muscle, and flexibility of activation patterns across various types of contractions. Current data are limited and these limitations influence our ability to interpret adaptations in muscle function in health and disease.

Electromyographic and Kinetic Analysis of Traditional, Chain, and Elastic Band Squats

Article

Full-text available

Dec 2002

This study examined mean integrated electromyography (I-EMG) for the quadriceps and hamstring muscle groups, as well as mean and peak vertical ground reaction forces (GRFs), for 3 conditions of the back squat. Conditions included (a) squat with barbell and weight plates, (b) squat with barbell and weight plates plus chains hung on each end of the barbell to replace approximately 10% of the squat load, and (c) squat with barbell and weight plates plus elastic bands offering resistance equivalent to approximately 10% of the squat load. Weight plates equal to the load added by either the chains or elastic bands were removed for the latter 2 squat conditions. Vertical GRFs were obtained during a single testing session for all 3 squat conditions. The tests were performed on a 2-cm thick aluminum platform (0.76 x 1.0 m) bolted directly to a force plate (OR6-5-2000, AMTI, Watertown, MA). Surface electrode I-EMG data from the quadriceps and hamstrings were recorded at 500 Hz. The exercise order was randomly determined for 11 NCAA Division I athletes who had experience using these types of squats. A repeated measures analysis of covariance revealed no differences in I-EMG and GRF during the eccentric or concentric phase for any of the 3 squat conditions. Analyses showed that mean GRF and I-EMG was significantly different between eccentric and concentric phases for all groups. The results question the usefulness of performing squats combining barbell and weight plates with chain and elastic resistance.

Strength Band Training

Book

Jan 2020

The top resource on strength band training is now expanded, updated, and better than ever! Whether you are training in the gym, at home, or on the road, Strength Band Training will show you how to maximize strength, speed, and flexibility. Featuring more than 160 exercises and 27 fitness and sport-specific workouts, you will discover why strength bands are the ultimate tool for targeting, isolating, rehabilitating, and developing every major muscle group. In this third edition, you will find a strength assessment index to measure your progress, new chapters on training for older adults and rehabilitation, training tips connecting research to specific exercises, and injury prevention recommendations. Full-color photo sequences accompany the detailed descriptions of each exercise, ensuring safe and proper execution. The exercises allow you to add resistance in multiple directions for routines that simulate sport-specific demands, improve strength, enhance movement, or target muscles to help prevent or recover from common injuries. Whether you are using flat bands or tubing, seeking performance gains or muscle mass, Strength Band Training provides authoritative advice, the most effective exercises, and proven workouts to achieve your goals.

Designing Resistance Training Programs

Book

Jan 2014

Designing Resistance Training Programs, Fourth Edition, is a guide to developing individualized training programs for both serious athletes and fitness enthusiasts. Two of the world’s leading experts on strength training explore how to design scientifically based resistance training programs, modify and adapt programs to meet the needs of special populations, and apply the elements of program design in the real world. The fourth edition presents the most current information while retaining the studies that are the basis for concepts, guidelines, and applications in resistance training. Meticulously updated and heavily referenced, the fourth edition contains the following updates: A full-color interior provides stronger visual appeal.Sidebars focus on a specific practical question or an applied research concept, allowing readers to connect research to real-life situations.Multiple detailed tables summarize research from the text, offering an easy way to compare data and conclusions.A glossary makes it simple to find key terms in one convenient location.Newly added instructor ancillaries make the fourth edition a true learning resource for the classroom (available at www.HumanKinetics.com/DesigningResistanceTrainingPrograms). Designing Resistance Training Programs, Fourth Edition, is an essential resource for understanding and applying the science behind resistance training for any population.

Fundamentals of biomechanics: Equilibrium, motion, and deformation, fourth edition

Book

Jan 2016

This textbook integrates the classic fields of mechanics-statics, dynamics, and strength of materials-using examples from biology and medicine. The book is excellent for teaching either undergraduates in biomedical engineering programs or health care professionals studying biomechanics at the graduate level. Extensively revised from a successful third edition, Fundamentals of Biomechanics features a wealth of clear illustrations, numerous worked examples, and many problem sets. The book provides the quantitative perspective missing from more descriptive texts, without requiring an advanced background in mathematics. It will be welcomed for use in courses such as biomechanics and orthopedics, rehabilitation and industrial engineering, and occupational or sports medicine. This book: • Introduces the fundamental concepts, principles, and methods that must be understood to begin the study of biomechanics • Reinforces basic principles of biomechanics with repetitive exercises in class and homework assignments given throughout the textbook • Includes over 100 new problem sets with solutions and illustrations.

Training with rubber bands

Article

Dec 2004

Brian W. Findley

The use of bands in strength training may provide more resistance in sport-specific training, but they may also hinder range of motion and muscle growth.

Engineering Materials 2: An Introduction to Microstructures, Processing and Design: Second Edition

Article

Jan 2013

Materials are evolving faster today than at any time in history. As a consequence the engineer must be more aware of materials and their potential than ever before. In comparing the properties of competing materials with precision involves an understanding of the basic properties of materials, how they are controlled by processing, formed, joined and finished and of the chain of reasoning that leads to a successful choice. This book will provide the reader with this understanding. Materials are grouped into four classes: Metals, Ceramics, Polymers and Composites, and each are examined in turn. The chapters are arranged in groups, with a group of chapters to describe each of the four classes of materials. Each group first of all introduces the major families of materials that go to make up each materials class. The main microstructural features of the class are then outlined and the reader is shown how to process or treat them to get the structures (properties) that are wanted. Each group of chapters is illustrated by Case Studies designed to help the reader understand the basic material. This book has been written as a second level course for engineering students. It provides a concise introduction to the microstructures and processing of materials and shows how these are related to the properties required in engineering design. © Michael F. Ashby and David R. H. Jones 1998. All rights reserved.

Biomechanical Factors in Human Strength

Article

Feb 1994

Everett Harman

Roundtable Discussion: Machines Versus Free Weights

Article

Dec 2000

Guy Gregory Haff

Many strength and conditioning professionals design and implement resistance training programs that involve both free-weights and weight machines. These programs are often designed in an attempt to improve strength, power, and ultimately athletic performance. The benefits of both modalities of resistance training are often discussed by athletes, coaches, athletic trainers, and sport scientists. In these discussions, there are many differing opinions about which modality or combination of modalities produces optimal sports performance gains. The purpose of this roundtable is to discuss several issues related to the use of free-weight and machine modalities in an athletic setting.

Concept of the Law of Bone Remodelling

Chapter

Jan 1986

Jullius Wolff

Between 1870 and 1872, I attempted to demonstrate that when the external shape of the bone and its static stressing are altered pathologically by any external or internal cause, certain changes in the internal architecture of the bone take place and that, in similar instances, the same change occurs.

Sport and Exercise Biomechanics

Book

Jan 2006

Strength and conditioning

Article

Jan 2002

Current information and evidence indicate that for most activities free weight training can produce superior results compared to training with machines, particularly when the free weight training involves complex, multi‐joint exercises. A number of reasons can account for the superiority of free weights; the major factor deals with mechanical specificity. Mechanical specificity is concerned with appropriate movement patterns, force application and velocity of movement. Considering the available evidence that adherence to the concept of specificity of exercise and training can result in a greater transfer of training effect then free weights should produce a more effective training transfer. Therefore, the majority of resistance exercises making up a training programme should include of free weight exercises with emphasis on mechanical specificity (i.e. large muscle mass exercises, appropriate velocity, contraction type etc.). Generally, machines should be used as an adjunct to free weight training and, depending upon the sport, can be used to a greater or lesser extent during various phases of the training period (preparation, pre‐competition, competition).

Human Torque Capability Versus Machine Resistive Torque for Four Eagle Resistance Machines

Article

Aug 1990

Since human torque capability (HTC) varies throughout a range of joint motion, manufacturers of strength training equipment have attempted to design machines which provide resistance that varies in similar patterns. The purpose of this study was to perform a qualitative biomechanical analysis on four Eagle (Cybex; P.O. Box 9003, Ronkonkoma, New York) machines to determine if the machine resistive torque (MR7) matches the HTC of female athletes. Ten fe'male subjects were tested for HTC during knee extension, knee flexion, elbow extension and elbow flexion. The MRTpatterns of the four machines were determined by analyzing 35 mm photographs of the cams. The data was normalized to percent of maximum and the MRT was superimposed over the HTC curve for each machine. There was general correspondence between the MRT and HTC with some specific exceptions. The knee flexion machine MRT most closely matched HTC. The MRTs of the knee and elbow extension machines were slightly higher than the HTCs at the beginning and end of the range of motion. The peak MRT of the elbow flexion machine did not accommodate the peak HTC. Slight modifications in the cams may be necessary to improve the matching of MRT and HTC. © 1990 Journal of Applied Sport Science Research. All rights reserved.

Resistance Training Modes: A Biomechanical Perspective

Article

Apr 1994

Everett Harman

Facility Considerations: Advantages and disadvantages of isokinetics, variable resistance and free weights

Article

Feb 1985
Natl Strength Condit Assoc J

Bill Foran

The Law of Bone Remodeling

Book

Jan 1892

J. L. Wolff

Science and Practice of Strength Training

Book

Jan 2005

Exercise Physiology: Energy, Nutrition, and Human Performance, 3rd Edition

Article

Dec 1991

Strength Training Modes: Dynamic Variable Resistance and the Universal System

Article

Aug 1982

Frank Smith

“Balanced, total body conditioning;” “functional strength, power, muscle endurance and flexibility;” and “cardiovascular/cardiorespiratory efficiency” are the watchwords of Universal’s training philosophy. Muscle strength alone is not enough for optimal athletic performance. What is crucial for the athlete is the ability to use that strength in competitive situations and to “go the distance” successfully. High standards of health and physical fitness, as well as strength, are integral to Universal’s conditioning programs.

Neuromechanical Basis of Kinesiology, 2nd Edition

Article

Nov 1995

Roger Enoka

Resistive Torque Analysis of 5 Nautilus Exercise Machines

Article

Jan 1983

Everett Harman

Physical Activity Programs and Behavior Counseling in Older Adult Populations

Article

Nov 2004

Physical activity offers one of the greatest opportunities for people to extend years of active independent life and reduce functional limitations. The purpose of this paper is to identify key practices for promoting physical activity in older adults, with a focus on older adults with chronic disease or low fitness and those with low levels of physical activity. Key practices identified in promotion activity in older adults include: 1) A multidimensional activity program that includes endurance, strength, balance, and flexibility training is optimal for health and functional benefits; 2) Principles of behavior change, including: social support, self-efficacy, active choices, health contracts, assurances of safety, and positive reinforcement enhance adherence; 3) Management of risk by beginning at low intensity but gradually increasing to moderate physical activity, which has a better risk-to-benefit ratio and should be the goal for older adults; 4) An emergency procedure plan is prudent for community based programs; and 5) Monitoring aerobic intensity is important for progression and for motivation. Selected content review of physical activity programming from major organizations and institutions are provided. Regular participation in physical activity is one of the most effective ways for older adults, including those with disabilities, to help prevent chronic disease, promote independence, and increase quality of life in old age.

Using Chains for Strength and Conditioning

Article

Oct 2004

summary: To maximize gains in size, speed, and strength, coaches may utilize alternative methods of training. Anecdotal evidence exists suggesting the effectiveness of chains as a resistance training modality. This article discusses that evidence as well as practical methods of incorporating chains in a resistance training program. (C) 2004 National Strength and Conditioning Association

Contractile Performance of Skeletal Muscle Fibres

Chapter

Jan 2008

K A Paul Edman

Structure of the force generating systemMolecular events during contractionContractile performance of striated muscleReferences

Methods to Increase the Effectiveness of Maximal Power Training for the Upper Body

Article

Dec 2005

Power training recommendations have typically involved Olympic Weightlifting and plyometric exercise prescriptions, paying scant attention to upper body maximal-power demands. This article attempts to redress this situation by focusing upon strategies and specific techniques that can be implemented to enhance the effectiveness of upper body maximal-power training.

Exercise Physiology: Energy, nutrition and human performance

Article

Jan 1992

Engineering Materials : An Introduction to Microstructures, Processing and Design / M.F. Ashby, D.R.H. Jones.

Article

Jan 1988

Introducción a las microestructuras y al procesamiento de materiales de ingeniería, así como las relaciones que aquéllos tienen con las propiedades requeridas para el diseño de ingeniería.

Variable resistance versus constant resistance strength training in adult males

Article

Aug 1978
Eur J Appl Physiol Occup Physiol

Thomas V. Pipes

Changes in strength, body composition and anthropometric measures for groups training with constant resistance and variable resistance training procedures was compared. Thirty-six male volunteers were randomly assigned to one of three groups: Constant Resistance (CR), Variable Resistance (VR) and Control (C). Strength training was conducted 3 days per week, 45 min per day, for 10 weeks. The results demonstrated that both the CR and the VR groups increased muscular strength. The CR group demonstrated significant increases in strength over the VR group when strength was assessed by CR procedures. Conversely, the VR group demonstrated significant increases in strength over the CR group when strength was assessed by VR procedures. Neither group exhibited superiority over the other relative to changes in body composition and anthropometric measures. The significance of these results is discussed.

A comparison of knee extensor strength curves obtained theoretically and experimentally

Article

Feb 1991

Strength curves relate a measure of maximal voluntary force of a group of synergistic muscles, typically a resultant knee joint moment, to a measure of muscular length, typically a joint angle. In this study, it was hypothesized that the shape of strength curves is primarily determined by the force-length properties of the individual muscles within a synergistic group. This hypothesis was tested for knee extensor strength curves by comparing theoretically determined strength curves based on the force-length relations of the individual muscles with those obtained experimentally. The agreement between theoretical and experimental curves was good, suggesting that the initial hypothesis was correct. Accepting this result, it is possible to determine the contribution of individual muscles to the total force of the synergistic group. This information, in turn, may be utilized for practical applications in sports or for evaluating strength curves of patients with injuries or diseases of the musculoskeletal system.

In vivo muscular force analysis during the isometric flexion on a monkey's elbow

Article

Feb 1988
J BIOMECH

An experimental method has been developed to analyse muscular forces and torques in vivo during isometric flexion of the elbow in small monkeys (Macaca fascicularis). A mini-transducer was built with a view to measure forces in situ, without cutting tendons. The positions of tendon insertions were measured on anatomical parts, then integrated in a series of calculations aiming of deducing the lever arms of forces to be included in a torque equilibrium relationship. Muscle activity of the three main flexors was measured for five angles of isometric flexion between 70 degrees and 110 degrees, 0 degrees corresponding to the full extended forearm. The analysed signals were selected using physiological and biomechanical criteria. Then, results corresponding to force participation, and torque participations, were worked out; they are presented and discussed in the present paper.

Human Strength Curves

Article

Feb 1984

Resistive training.

Article

Apr 1983
CLIN SPORT MED

Gideon B. Ariel

The advent of computers made it possible to design exercise equipment with artificial intelligence, enabling the computerized machine to select the best exercise method based on each individual user. The underlying principle is that of a computer-controlled feedback that is able to maintain any desired pattern of force and motion throughout the range of each exercise, regardless of the magnitude or rate of force applied by the person exercising. Such a system has many advantages over existing resistive exercise mechanisms.

Effects of lifting rate on elbow torques exerted during arm curl exercises

Article

Feb 1983

The purpose of this study was to determine and compare the resultant joint torques exerted during similar arm curl exercises performed at slow, medium, and fast rates of lifting using a barbell and a weight machine. Three men experienced in strength-training performed lifts under nine different conditions of load and rate of lifting. The resultant torque at the elbow was determined for one trial under each condition. The following conclusions appear to be warranted: 1. For the seated arm curls performed with a barbell, the resultant elbow torques, exerted at all but the extremes of the range of motion, were independent of the rate of lifting. For arm curls performed with a Universal weight machine, the elbow torques required to lift a given load were independent of the rate of lifting except when the duration of the lift was less than 2 s. 2. Inertial effects were greatest at fast lifting rates and declined asymptotically as the rate of lifting decreased. 3. Because the form of the results for all three subjects was essentially the same despite pronounced differences in the subjects’ heights and weights, conclusions based on an analysis of the performances of any other subjects experienced in weight training would probably be the same as those reached in the present study. If it is accepted that muscular strength can best be increased by repeatedly requiring the muscles to produce forces close to the maximum of which they are capable, as the Overload Principle states, the results obtained in this study also suggest that: 1. For a given load, a fast rate of lifting is likely to yield a slightly better rate of strength development than slower rates of lifting. 2. Neither of the two pieces of equipment used in the study is inherently superior to the other in terms of strength development.

Changes in pennation with joint angle and muscle torque: In vivo measurements in human brachialis muscle

Article

May 1995

1. Estimates of pennation in human muscles are usually obtained from cadavers. In this study, pennation of human brachialis was measured in vivo using sonography. Effects of static and dynamic changes in elbow angle and torque were investigated. 2. Pennation was measured in eight subjects using an 80 mm, 5 MHz, linear-array ultrasound transducer to generate sagittal images of the brachialis during maximal and submaximal isometric contractions at various elbow angles. It was shown that estimates of pennation were reproducible, representative of measurements made throughout the belly of the muscle and not distorted by compression of the muscle with the transducer or rotation of the muscle out of the plane of the transducer. 3. Mean resting pennation was 9.0 +/- 2.0 deg (S.D., range 6.5-12.9 deg). When the muscle was relaxed there was no effect of elbow angle on pennation. However, during a maximal isometric contraction (MVC), with the elbow flexed to 90 deg, pennation increased non-linearly with elbow torque to between 22 and 30 deg (mean 24.7 +/- 2.4 deg). The effect of increasing torque was small when the elbow was fully extended. The relationship between elbow angle, elbow torque and brachialis pennation suggests that the relaxed brachialis muscle is slack over much of its physiological range of lengths. 4. There was no hysteresis in the relationship between torque and pennation during slow isometric contractions (0.2 MVC s-1), and the relationship between elbow angle and pennation was similar during slow shortening and lengthening contractions. 5. Two consequences follow from these findings. Firstly, intramuscular mechanics are complex and simple planar models of muscles underestimate the increases in pennation which occur during muscle contraction. Second, spindle afferents from relaxed muscles may not encode joint angle over the full range of movement.

A Kinematic and Electromyographic Study of Shoulder Rehabilitation Exercises

Article

Apr 1993

The role of shoulder muscles during passive, active, and resistive phases of shoulder rehabilitation exercises was investigated in ten normal subjects with no history of shoulder pathology. Using the scapular plane as a reference, three-dimensional motion of the shoulder was recorded with a computer-aided motion analysis system (VICON) to determine total shoulder elevation. Simultaneously, electromyographic data were acquired on nine shoulder muscles while performing the three phases of shoulder rehabilitation exercises as described by Neer. Fine wire intramuscular electrodes were placed in the following muscles: trapezius, serratus anterior, deltoid (anterior, middle, and posterior separately), supraspinatus, infra-spinatus, biceps, and latissimus dorsi. Phase I (passive) exercises performed in the supine position showed the least electromyography (EMG) activity. There was a gradation of KMG activity as one progressed from Phase I (passive) to Phase II (active) to Phase III (resistive) shoulder exercises. Isometric exercises and Phase III resistive exercises showed high levels of activity in the rotator cuff and deltoid muscles. Supine Phase I exercises should be considered in the early postoperative period after shoulder surgery to achieve maximum motion while minimizing shoulder muscle activity. Progression to Phase II and Phase III exercises may proceed as soft tissue and bony healing permit. Phase III exercises performed with an elastic band should provide a satisfactory method to strengthen these muscles. (C) Lippincott-Raven Publishers.

Comparison of Tibiofemoral Joint Forces during Open-Kinetic-Chain and Closed-Kinetic-Chain Exercises.

Article

May 1993

The purpose of this study was to analyze forces at the tibiofemoral joint during open and closed-kinetic-chain exercises. Five healthy subjects performed maximum isometric contractions at 30, 60, and 90 degrees of knee flexion during open-kinetic-chain extension, open-kinetic-chain flexion, and closed-kinetic-chain exercises. Electromyographic activity of the quadriceps and hamstrings, as well as load and torque-cell data, were recorded. Tibiofemoral shear and compression forces were calculated with use of a two-dimensional biomechanical model. The results showed that, during the open-kinetic-chain extension exercise, maximum posterior shear forces (the resisting forces to anterior drawer) of 285 +/- 120 newtons (mean and standard deviation) occurred at 30 degrees of knee flexion and maximum anterior shear forces (the resisting forces to posterior drawer) of 1780 +/- 699 newtons occurred at 90 degrees of knee flexion. The closed-kinetic-chain exercise produced significantly less posterior shear force at all angles when compared with the open-kinetic-chain extension exercise. In addition, the closed-kinetic-chain exercise produced significantly less anterior shear force at all angles except 30 degrees when compared with the open-kinetic-chain flexion exercise (p < 0.05). Analysis of tibiofemoral compression forces and electromyographic recruitment patterns revealed that the closed-kinetic-chain exercise produced significantly greater compression forces and increased muscular co-contraction at the same angles at which the open-kinetic-chain exercises produced maximum shear forces and minimum muscular co-contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Neural Adaptations with Chronic Physical Activity

Article

Jun 1997
J BIOMECH

Roger Enoka

Chronic activity patterns, such as strength training, limb immobilization, and aging, produce marked adaptations in both the muscular and nervous systems. In this brief review, some of the involved mechanisms are examined as they are revealed through studies on the maximality, specificity, and pattern of the neural drive to muscle. The studies on maximality indicate that it is difficult to activate maximally a muscle by voluntary command, the capacity varies across muscles, tasks, and training, and the maximum discharge rates of motor neurons decreases with immobilization and increases with strength training. The data on specificity demonstrate that: strength can be increased by training with imagined contractions; the velocity specificity of isokinetic training is evident with intended contractions; the strength training influences the untrained homologous muscle in the contralateral limb; the bilatral deficit can become a bilateral facilitation with appropriate training; and that eccentric contractions appear to involve a different activation scheme compared to isometric and concentric contractions. Finally, the literature on the pattern of the neural drive suggests that: coactivation varies with training and often decreases as skill level increases; measures of motor-unit synchronization reveal changes in neuronal connectivity with physical training; the reflex potentiation varies across muscles, individuals, and activity patterns; the modulation of the H-reflex amplitude with training involves changes in the motor neuron; and the motor neurons exhibit a bistable, excitability property that may be influenced by exercise. Despite the breadth of this evidence, there remain substantial gaps in our knowledge, particularly regarding the symmetry of adaptations with increased and decreased chronic physical activity.

Effects of Theraband and Lightweight Dumbbell Training on Shoulder Rotation Torque and Serve Performance in College Tennis Players

Article

Jul 1998
AM J SPORT MED

The purpose of this study was to determine whether a 4-week isotonic resistance training program using Theraband elastic tubing and lightweight dumbbells would significantly increase concentric shoulder rotator strength or velocity of serve or both in a group of elite-level tennis players. Twenty-two male and female varsity college tennis players were randomly assigned to control or 4-week training groups. Subjects were pre- and posttested in concentric internal and external rotation torque using an isokinetic dynamometer. Functional performance was assessed before and after training by recording the peak and average velocities of eight maximal serves. The experimental group exhibited significant gains in internal rotation torque at both slow (120 deg/sec) and fast speeds (300 deg/sec) for total work and in peak torque to body weight ratio and torque acceleration energy at the fast speed. This group also exhibited significant gains in external rotation torque for the same parameters at fast speed. Regarding speed to serve, the experimental group exhibited significantly greater increase in peak speed (+6.0% compared with -1.8%) and average speed (+7.9% compared with -2.3%) compared with the control group. Men exhibited greater internal and external rotation torque on all parameters and in peak and mean speed of serve on both evaluations. Men also exhibited greater imbalance in external to internal rotation torque ratios. In conclusion, resistance training using Theraband tubing and lightweight dumbbells may have beneficial effects on strength and functional performance in college-level tennis players.

The Effects of Strength Training on Strength and Health-Related Quality of Life in Older Adult Women

Article

Jan 2000

The short-term effects of an accessible exercise intervention on the strength and health-related quality of life (HRQOL) among older adult women were evaluated. We conducted an 8-week resistance training intervention utilizing elastic bands in 62 community-dwelling women with a mean age of 68 years. Participants were randomly assigned to either an exercise or a control group. Pre- and postintervention assessments included strength tests and HRQOL. Results revealed significant increases in three major muscles compared to the control group. However, there were no significant changes on either mental or physical health functioning. The elastic bands provide older adult women with an inexpensive, practical exercise program that effectively increases strength within 8 weeks but may have little effect on self-reported HRQOL.

Electromyographic biofeedback-controlled exercise versus conservative care for patellofemoral pain syndrome

Article

Jan 2002
ARCH PHYS MED REHAB

To determine the effects of electromyographic biofeedback treatment in patients with patellofemoral pain syndrome. Randomized controlled trial. A physical medicine and rehabilitation department in a research hospital of a university referral center. Sixty patients with patellofemoral pain syndrome. Patients were randomly placed into 2 groups: biofeedback group (n = 30) and a control group (n = 30). The biofeedback group received electromyographic biofeedback training and a conventional exercise program, whereas the control group received a conventional exercise program only. Maximum and mean contraction values of the vastus medialis and the vastus lateralis muscles were assessed with the biofeedback device. Pain and functional status of the patients were measured by a visual analog scale (VAS) and the Functional Index Questionnaire (FIQ), respectively. Contraction values improved significantly at the end of the first month, compared with the pretreatment values in both groups. Mean contraction values in the biofeedback group of the vastus medialis muscles in all 3 monthly measurements, and the vastus lateralis muscles at the end of the first month, were significantly higher than those of the control group. Significant improvements were shown for both the VAS and the FIQ in both groups. Monthly follow-ups showed no VAS and FIQ differences between the groups. Electromyographic biofeedback treatment did not result in further clinical improvement when compared with a conventional exercise program in patients with patellofemoral pain syndrome.

The effects of bungy weight training on muscle function and functional performance

Article

Feb 2003

Eccentric strength training is thought to be important for improving functional performance. A form of training that may enhance the eccentric training stimulus is the attachment of a rubber bungy to the strength-training apparatus in such a way that the return velocity and, therefore, the force required to decelerate the load at the end of the eccentric phase are increased. To determine the effects of elastic bungy training, we performed two studies. In the first, we examined the electromyographic (EMG) and kinematic characteristics of three different squat techniques: traditional squat, non-bungy jump squat and bungy jump squat. In the second study, we examined whether jump squat training with and without the attachment of a rubber bungy to an isoinertial supine squat machine affects muscle function, multidirectional agility, lunge ability and single leg jump performance. The EMG activity of the vastus lateralis and gastrocnemius muscles was recorded. An instrumented isoinertial supine squat machine was used to measure maximal strength and various force, velocity and power measures in both studies. Participants were randomly assigned to one of three groups: a control group and two weight-trained groups, one of which performed bungy squat jumps and one of which performed non-bungy squat jumps. The two experimental groups performed 10 weeks of ballistic weight training. The kinematic and EMG characteristics of the bungy and non-bungy squat techniques differed significantly from those of the traditional squat on all the variables measured. The only difference between the bungy squat and non-bungy squat training was greater EMG activity during the later stages (70-100%) of the eccentric phase of the bungy squat condition. The 10 weeks of bungy squat and non-bungy squat jump weight training were found to be equally effective in producing improvements in a variety of concentric strength and power measures (10.6-19.8%). These improvements did not transfer to improved performance for the single leg jump and multidirectional agility. However, bungy weight training did lead to a significant improvement in lunge performance (21.5%) compared with the other groups.

Forms of Variable Resistance Training

Abstract

No full-text available

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