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Neuromuscular Adaptations to Same-Session Combined Endurance and Strength Training in Recreational Endurance Runners
Abstract
This study examined neuromuscular adaptations in recreational endurance runners during 24 weeks of same-session combined endurance and strength training (E+S, n=13) vs. endurance training only (E, n=14). Endurance training was similar in the 2 groups (4-6x/week). Additional maximal and explosive strength training was performed in E+S always after incremental endurance running sessions (35-45 min, 65-85% HRmax). Maximal dynamic leg press strength remained statistically unaltered in E+S but decreased in E at week 24 (-5±5%, p=0.014, btw-groups at week 12 and 24, p=0.014 and 0.011). Isometric leg press and unilateral knee extension force, EMG of knee extensors and voluntary activation remained statistically unaltered in E+S and E. The changes in muscle cross-sectional (CSA) differed between the 2 groups after 12 (E+S+6±8%, E -5±6%, p<0.001) and 24 (E+S+7±7%, E -6±5%, p<0.001) weeks. 1 000 m running time determined during an incremental field test decreased in E+S and E after 12 (-7±3%, p<0.001 and -8±5%, p=0.001) and 24 (-9±5%, p=0.001 and -13±5%, p<0.001) weeks. Strength training performed always after an endurance running session did not lead to increased maximal strength, CSA, EMG or voluntary activation. This possibly contributed to the finding of no endurance performance benefits in E+S compared to E.
© Georg Thieme Verlag KG Stuttgart · New York.
... Nine studies [8, 13-15, 18, 26, 28, 33, 53] exclusively examined trained distance runners and ten studies examined untrained (i.e. recreational) runners only [10,20,21,23,31,32,[54][55][56][57]. The remaining studies included a combination of untrained and trained distance runners [9,12,16,25,58,59]. ...
... Articles after title and abstract screening: n = 69 Attempts to contact corresponding authors [14,18,21,28,31,54,56,57] were made when studies suggested that data had been collected on variables of interest; however, follow-up data had not been published or were not reported adequately for this analysis (e.g. graphed data). ...
... Most studies failed to list eligibility criteria (item 1, 75%) and intention-to-treat analysis (item 9, 56%). Nine studies did not randomly allocate participants [4,8,18,21,28,31,54,56,57]. ...
Background
Concurrent strength and endurance (CSE) training improves distance running performance more than endurance training alone, but the mechanisms underpinning this phenomenon are unclear. It has been hypothesised that biomechanical or neuromuscular adaptations are responsible for improvements in running performance; however, evidence on this topic has not been synthesised in a review.
Objective
To evaluate the effect of CSE training on biomechanical and neuromuscular variables in distance runners.
Methods
Seven electronic databases were searched from inception to November 2018 using key terms related to running and strength training. Studies were included if the following criteria were met: (1) population: ‘distance’ or ‘endurance’ runners of any training status; (2) intervention: CSE training; (3) comparator: running-only control group; (4) outcomes: at least one biomechanical or neuromuscular variable; and, (5) study design: randomised and non-randomised comparative training studies. Biomechanical and neuromuscular variables of interest included: (1) kinematic, kinetic or electromyography outcome measures captured during running; (2) lower body muscle force, strength or power outcome measures; and (3) lower body muscle–tendon stiffness outcome measures. Methodological quality and risk of bias for each study were assessed using the PEDro scale. The level of evidence for each variable was categorised according to the quantity and PEDro rating of the included studies. Between-group standardised mean differences (SMD) with 95% confidence intervals (95% CI) were calculated for studies and meta-analyses were performed to identify the pooled effect of CSE training on biomechanical and neuromuscular variables.
Results
The search resulted in 1578 potentially relevant articles, of which 25 met the inclusion criteria and were included. There was strong evidence that CSE training significantly increased knee flexion (SMD 0.89 [95% CI 0.48, 1.30], p < 0.001), ankle plantarflexion (SMD 0.74 [95% CI 0.21–1.26], p = 0.006) and squat (SMD 0.63 [95% CI 0.13, 1.12], p = 0.010) strength, but not jump height, more than endurance training alone. Moderate evidence also showed that CSE training significantly increased knee extension strength (SMD 0.69 [95% CI 0.29, 1.09], p < 0.001) more than endurance training alone. There was very limited evidence reporting changes in stride parameters and no studies examined changes in biomechanical and neuromuscular variables during running.
Conclusions
Concurrent strength and endurance training improves the force-generating capacity of the ankle plantarflexors, quadriceps, hamstrings and gluteal muscles. These muscles support and propel the centre of mass and accelerate the leg during running, but there is no evidence to suggest these adaptations transfer from strength exercises to running. There is a need for research that investigates changes in biomechanical and neuromuscular variables during running to elucidate the effect of CSE training on run performance in distance runners.
... The Physiotherapy Evidence Database (PEDro) scale was subsequently used to assess the quality of the remaining 26 records [31-33, 36, 38, 72-92] by the two independent reviewers. Two studies reported their results across two papers [32,38,90,92], therefore both are considered as single studies hereafter, thus a total of 24 studies were analyzed. The PEDro scale is a tool recommended for assessing the quality of evidence when systematically reviewing randomized-controlled trials [93]. ...
... A summary of the participant characteristics for the 24 studies which met the criteria for inclusion in this review is presented in Table 1. A total of 469 participants (male [31,72,76,81,83,84,86,[90][91][92], well-trained participants in ten studies [32,33,36,38,73,75,79,80,85,88,89], and highly-trained or national/international runners were used in four studies [74,77,82,87]. National caliber junior runners were also used in one investigation [78]. ...
... Fourteen studies provided detailed accounts of the running training undertaken by the participants. However, these were usually reported from monitoring records, thus only three studies were deemed to have appropriately controlled for the volume and intensity of running in both groups [32,38,73,80,90,92]. Six studies provided little or no detail on the running training that participants performed [31,33,82,84,86,91]. ...
Background
Middle- and long-distance running performance is constrained by several important aerobic and anaerobic parameters. The efficacy of strength training (ST) for distance runners has received considerable attention in the literature. However, to date, the results of these studies have not been fully synthesized in a review on the topic. Objectives
This systematic review aimed to provide a comprehensive critical commentary on the current literature that has examined the effects of ST modalities on the physiological determinants and performance of middle- and long-distance runners, and offer recommendations for best practice. Methods
Electronic databases were searched using a variety of key words relating to ST exercise and distance running. This search was supplemented with citation tracking. To be eligible for inclusion, a study was required to meet the following criteria: participants were middle- or long-distance runners with ≥ 6 months experience, a ST intervention (heavy resistance training, explosive resistance training, or plyometric training) lasting ≥ 4 weeks was applied, a running only control group was used, data on one or more physiological variables was reported. Two independent assessors deemed that 24 studies fully met the criteria for inclusion. Methodological rigor was assessed for each study using the PEDro scale. ResultsPEDro scores revealed internal validity of 4, 5, or 6 for the studies reviewed. Running economy (RE) was measured in 20 of the studies and generally showed improvements (2–8%) compared to a control group, although this was not always the case. Time trial (TT) performance (1.5–10 km) and anaerobic speed qualities also tended to improve following ST. Other parameters [maximal oxygen uptake (\(\dot{V}{\text{O}}_{{2{ \hbox{max} }}}\)), velocity at \(\dot{V}{\text{O}}_{{2{ \hbox{max} }}}\), blood lactate, body composition] were typically unaffected by ST. Conclusion
Whilst there was good evidence that ST improves RE, TT, and sprint performance, this was not a consistent finding across all works that were reviewed. Several important methodological differences and limitations are highlighted, which may explain the discrepancies in findings and should be considered in future investigations in this area. Importantly for the distance runner, measures relating to body composition are not negatively impacted by a ST intervention. The addition of two to three ST sessions per week, which include a variety of ST modalities are likely to provide benefits to the performance of middle- and long-distance runners.
... The performance of runners can be described as a multifactorial phenomenon (Beattie, Carson, Lyons, Rossiter, & Kenny, 2017), although several researchers have leveraged the importance of physiological and biomechanical factors to the performance of this population of endurance athletes (Balsalobre-Fernández, Santos-Concejero, & Grivas, 2016;Beattie, et al., 2017;Denadai, de Aguiar, de Lima, Greco, & Caputo, 2016;Enoksen, Shalfawi, & Tønnessen, 2011;Lum, Tan, Pang, & Barbosa, 2016;Mikkola, et al., 2011;Schumann, Pelttari, Doma, Karavirta, & Häkkinen, 2016;Taipale, et al., 2010). Therefore, the understanding of the manipulation and control of the physiological indexes associated to the performance of endurance runners is of utmost importance in making them useful tools for the training prescription (Camic, Hahn, Hendrickson, & Jagim, 2017;Guglielmo, Babel Junior, Arins, & Dittrich, 2012;), specifically in middle-distance runners, in which performance is determined primarily by the manipulation of aerobic and anaerobic capacities (Enoksen et al., 2011) and its prevalence at each stage of a test (Denadai, Ortiz, & Mello, 2004). ...
... However, when the RT stimulus/recovery ratio (such as maximum strength, explosive strength, plyometric training, and combined training) respects the principle of general adaptation syndrome, it can bring significant improvements in runner's performance (Balsalobre-Fernández, et al., 2016;Beattie, et al., 2017;Denadai, et al., 2016;Lum, et al., 2016;Mikkola, et al., 2011;Schumann, et al., 2016;Taipale, et al., 2010;Vorup, et al., 2016). In line with the above-mentioned authors' inferences that the adaptation (gain in strength) originates primarily from neural adaptations, we can attribute the significant performance improvement in the post 144 h session, when compared to baseline, to the improvement in neural control and improvement in coordination and co-activation of the lower limbs' musculature (Cheng, et al., 2012;Nummela, et al., 2006), to the improvement of central and peripheral control through an advance of pre-activation (muscle activation before foot impact with the soil and reflex facilitation during the late eccentric and early concentric phases), as well as to the improvement in the stretch reflex, which resulted in the improvement of the reactive force (Markovic & Mikulic, 2010). ...
The study aimed to identify the effect of a neuromuscular resistance training protocol (NRTP) on the performance of 5-km distance runners. This study included 18 male runners (age=29.3±3.2 years, fat percentage=11.3±2.6%, body height=1.77±.04 m, body mass=73.4±4.4 kg, time in 5 km=20.6±2.4 min, training years=4.3±0.7 years). First, volunteers were anthropometrically evaluated, and they performed one-repetition maximum (1RM) 45º leg press (LP) strength test. Second, they performed an incremental protocol in the 45º LP to acquire the electromyographic threshold. Third, they completed a 5-km time trial run (5 km basal). In the fourth session, they performed NRTP in LP. And fifth, the 5-km time trial run was performed at 30 min, 48 h, 96 h, and 144 h post the NRTP intervention. A significant decrease (p≤.05) was observed when baseline values were compared with post 30 min and post 48 h (p=.02 and p=.04, respectively). However, there were significant positive differences in performance (p=.04 for time) when baseline values and post 144 h were analyzed. Therefore, it is concluded that the NRTP can be used by 5-km distance runners to improve their performance with a break of one week between the intervention and test.
... After removing duplicate records, records not retrieved, and documents excluded after reading the title and/or abstract, 73 studies were assessed for eligibility. Upon full-text reading, 35 studies were excluded because of the following reasons: participants aged under 16 years [48][49][50][51][52][53] or injured before the intervention [54][55][56]; no comparator group [57][58][59][60][61][62][63][64][65][66]; ST method considered not includable (e.g., core strength training; flywheel and isokinetic eccentric training; local muscular endurance training) [67][68][69][70][71][72]; no relevant outcomes included (i.e., VO 2 max, vVO 2 max, MMSS, sprint capacity, running performance) [73][74][75][76]; repeated outcome results derived from secondary analysis publications [77][78][79][80]; or cross-sectional study [81,82]. As a result, 38 studies were included in the meta-analyses. ...
Background
The running performance of middle-distance and long-distance runners is determined by factors such as maximal oxygen uptake (VO2max), velocity at VO2max (vVO2max), maximum metabolic steady state (MMSS), running economy, and sprint capacity. Strength training is a proven strategy for improving running performance in endurance runners. However, the effects of different strength training methods on the determinants of running performance are unclear.
Objective
The aim of this systematic review with meta-analysis was to compare the effect of different strength training methods (e.g., high load, submaximal load, plyometric, combined) on performance (i.e., time trial and time until exhaustion) and its determinants (i.e., VO2max, vVO2max, MMSS, sprint capacity) in middle-distance and long-distance runners.
Methods
A systematic search was conducted across electronic databases (Web of Science, PubMed, SPORTDiscus, SCOPUS). The search included articles indexed up to November 2022, using various keywords combined with Boolean operators. The eligibility criteria were: (1) middle- and long-distance runners, without restriction on sex or training/competitive level; (2) application of a strength training method for ≥ 3 weeks, including high load training (≥ 80% of one repetition maximum), submaximal load training (40–79% of one repetition maximum), plyometric training, and combined training (i.e., two or more methods); (3) endurance running training control group under no strength training or under strength training with low loads (< 40% of one repetition maximum); (4) running performance, VO2max, vVO2max, MMSS and/or sprint capacity measured before and after a strength training intervention program; (5) randomized and non-randomized controlled studies. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A random-effects meta-analysis and moderator analysis were performed using Comprehensive meta-analysis (version 3.3.0.70).
Results
The certainty of the evidence was very low to moderate. The studies included 324 moderately trained, 272 well trained, and 298 highly trained athletes. The strength training programs were between 6 and 40 weeks duration, with one to four intervention sessions per week. High load and combined training methods induced moderate (effect size = − 0.469, p = 0.029) and large effect (effect size = − 1.035, p = 0.036) on running performance, respectively. While plyometric training was not found to have a significant effect (effect size = − 0.210, p = 0.064). None of the training methods improved VO2max, vVO2max, MMSS, or sprint capacity (all p > 0.072). Moderators related to subject (i.e., sex, age, body mass, height, VO2max, performance level, and strength training experience) and intervention (i.e., weeks, sessions per week and total sessions) characteristics had no effect on running performance variables or its determinants (all p > 0.166).
Conclusions
Strength training with high loads can improve performance (i.e., time trial, time to exhaustion) in middle-distance and long-distance runners. A greater improvement may be obtained when two or more strength training methods (i.e., high load training, submaximal load training and/or plyometric training) are combined, although with trivial effects on VO2max, vVO2max, MMSS, or sprint capacity.
... Among the biggest concerns typically brought up by athletes and coaches alike is the fear of gaining excessive body (muscle) mass that may especially be disadvantageous in weight-bearing disciplines, such as running and cross-country skiing. However, changes in muscle hypertrophy in endurance athletes performing a much higher endurance compared to the strength training volume are typically expected to be small (i.e., ~3-6%) over a period of 12 weeks [107,114,124]. Moreover, at least in strengthtrained athletes it was nicely shown that the changes in limb girth are related the overall endurance training volume, being as low as 1% after 6 weeks of training with three weekly endurance training sessions as compared to ~2% after only one concomitant endurance training session for the same muscle group [125]. ...
Endurance performance is characterized by numerous physiological and neuromuscular factors. In order to maximize training adaptations in well-trained and elite athletes and, thereby, improve endurance performance, athletes in various sports use high-intensity training (HIT) and strength training to enhance their performance. In this chapter, we highlight the importance of HIT and strength training on the endurance capacity by summarizing the current evidence. Furthermore, ready-to-use recommendations are provided.KeywordsEndurance performanceTraining programmingHIITStrength developmentNeuromuscular performance
... En 14 de las 15 investigaciones el entrenamiento concurrente generó las adaptaciones propias del trabajo exclusivo de fuerza y de resistencia. Tan solo en el estudio realizado por Schumann et al. (2016) se constató que la adicción de un programa de un entrenamiento de fuerza al programa de entrenamiento de resistencia de corredores aficionados, no generó hipertrofia ni incrementó los niveles de fuerza máxima. Los autores de esta investigación entienden que realizar una sesión de fuerza después del entrenamiento de resistencia imposibilitó la consecución de las adaptaciones propias de los trabajos de fuerza, debido a la fatiga acumulada. ...
El objetivo del estudio fue contrastar la veracidad de las siguientes creencias: 1-El entrenamiento de fuerza y resistencia es incompatible. 2-El entrenamiento de fuerza limita la flexibilidad. 3-Las rutinas divididas son más eficaces que las de cuerpo entero. 4-El entrenamiento de fuerza no es útil para la pérdida de peso, o la mejora de la composición corporal. Se realizó una búsqueda en las siguientes bases de datos: ProQuest, Google Scholar, Scopus, ScienceDirect y Web of Science. Los criterios de selección fueron: a) Artículos escritos en Español o en Inglés. b) Investigaciones primarias con metodología experimental o cuasi-experimental. c) Escritos entre el año 2015 y 2019, salvo para los apartados 2 y 3, que se amplió hasta 2000 y 1990 respectivamente, debido a la escasez de publicaciones. d) La población objeto de estudio fueron adultos sanos que no practicaban deporte a nivel profesional o semiprofesional. e) Artículos que recogen exclusivamente adaptaciones logradas mediante una intervención con entrenamiento. Analizados los estudios, se pudo determinar que en adultos sanos: 1- El entrenamiento de fuerza y resistencia es compatible. 2- El entrenamiento de fuerza no deteriora la flexibilidad, y podría incluso mejorarla. 3- En virtud de los estudios existente, las rutinas divididas y las de cuerpo entero son igualmente eficaces para incrementar la fuerza. Las rutinas de cuerpo entero podrían generar mayor hipertrofia muscular. 4- El entrenamiento de fuerza es eficaz en la mejora de la composición corporal, y podría tener un impacto positivo en biomarcadores cardiovasculares y metabólicos.Abstract. The purpose of the study was to verify the veracity of the following beliefs: 1-Resistance and endurance training are incompatible. 2-Resistance training reduces flexibility. 3-Split body routines are more effective than full-body routines. 4-Resistance training is not useful neither in weight loss programs, nor to change body composition. The following databases were searched: ProQuest, Google Scholar, Scopus, ScienceDirect and Web of Science. The selection criteria were: a) Articles written in Spanish or in English b) Primary research following an experimental or quasi-experimental methodology c) Written between 2015 and 2019, except for section 2 and 3, which was extended until 2000 and 1990 respectively, due to the shortage of publications d) The target population of study were healthy adults who did not practice sports at the professional or semi-professional level e) Papers which include only adaptations achieved through training interventions. Once the studies were analyzed, it was concluded that in healthy adults: 1-The combination of resistance and endurance training is compatible. 2- Strength training does not decrease flexibility, and it could even improve it. 3- On the basis of existing studies, split and full-body routines are equally effective in improving strength. Full-body routines could generate higher muscle hypertrophy. 4- Strength training is effective in improving body composition, and could make a positive impact on cardiovascular and metabolic biomarkers.
... Apesar destes achados, estudos sugerem que adaptações positivas em músculos específicos e que não foram avaliados possivelmente ocorreram (SCHUMANN et al., 2014(SCHUMANN et al., , 2016 FERNANDEZ, 2010;JOHNSTON et al., 1997;KELLY;BURNETT;NEWTON, 2008;MILLET et al., 2002;STØREN et al., 2008). Estes resultados podem ser justificados pelo curto período de intervenção (8 semanas) e/ou pela ausência de controle nutricional (HASKELL et al., 2007;SILLANPÄÄ et al., 2008). ...
O desempenho de corredores de longa-distância é estabelecido por uma complexa interação entre variáveis físicas, tais como consumo máximo de oxigênio, economia de corrida e limiares metabólicos. Sabe-se que o treinamento pliométrico e de longa-distância podem modificar a interação entre estas variáveis, porém, investigações adicionais sobre como ocorrem estas adaptações, bem como sua transferência para o desempenho são necessárias. Portanto, o presente estudo teve como objetivo investigar o efeito combinado do treinamento pliométrico e de longa-distância em variáveis constituintes do desempenho de corredores fundistas. A amostra foi composta por 23 corredores do sexo masculino, com idade entre 18 e 50 anos, especialistas em provas de 10-km, e divididos em dois grupos experimentais de treinamento: I) treinamento combinado (TP: pliométrico + longa-distância; n = 11); II) treinamento de longa-distância (TC: longa-distância; n = 12). Todos os atletas foram submetidos a três sessões de avaliações (momento 1 - pré), correspondentes as mensurações de parâmetros antropométricos, neuromusculares, cardiorrespiratórios (sessão 1 e 2), e de desempenho nos 10-km em pista (sessão 3). Após o término das avaliações iniciais, os atletas foram divididos de forma pareada nos grupos de treinamento combinado (TP) ou de longa-distância (TC) a partir do teste de desempenho obtido nos 10-km antes do início do treinamento, e em seguida, iniciaram as 8 semanas de treinamento. Ao final do protocolo experimental, os atletas foram reavaliados (momento 2 - pós), e os testes aplicados foram os mesmos da avaliação inicial. Os resultados do presente estudo demonstraram que não houve alterações nas variáveis antropométricas e de flexibilidade, com exceção do ângulo de fase. Em relação aos testes neuromusculares, foi encontrado aumento significativo nos saltos counter movement jump, squat jump e drop jump após o treinamento, independente do grupo analisado. A altura do drop jump 50cm foi menor no grupo pliométrico, quando comparado ao grupo de treinamento de longa-distância, independente do momento de avaliação. Quando analisado as variáveis biomecânicas, encontramos aumento do tempo de contato com o solo e da oscilação vertical (apenas 18 km.h-1), além de diminuição da frequência de passada (12, 16 e 18 km.h-1) e da rigidez da perna (10 a 18 km.h-1) após o treinamento, independente do grupo analisado. O grupo pliométrico apresentou aumento do tempo de contato com o solo (14 km.h-1), porém, apresentou reduções significativas na força relativa máxima (16 km.h-1) e na rigidez da perna (14 km.h-1). Nas variáveis fisiológicas, houve aumento da economia de corrida, do ponto de compensação respiratória e do pico de velocidade em esteira, porém, o consumo máximo de oxigênio manteve-se estável, nos dois grupos de treinamento investigados. O desempenho final e a percepção subjetiva de esforço no teste de 10-km também não foram alterados significativamente, porém, a estratégia de prova (trecho inicial e parciais) e pico de velocidade nos 10-km aumentaram após o período experimental. Em resumo, após o protocolo experimental, o grupo de treinamento combinado apresentou alterações semelhantes em variáveis constituintes do desempenho em corredores de 10-km, quando comparado ao grupo de treinamento de longa-distância.
... En 14 de las 15 investigaciones el entrenamiento concurrente generó las adaptaciones propias del trabajo exclusivo de fuerza y de resistencia. Tan solo en el estudio realizado por Schumann et al. (2016) se constató que la adicción de un programa de un entrenamiento de fuerza al programa de entrenamiento de resistencia de corredores aficionados, no generó hipertrofia ni incrementó los niveles de fuerza máxima. Los autores de esta investigación entienden que realizar una sesión de fuerza después del entrenamiento de resistencia imposibilitó la consecución de las adaptaciones propias de los trabajos de fuerza, debido a la fatiga acumulada. ...
Análisis de la veracidad de determinadas creencias asociadas habitualmente al entrenamiento de fuerza. Una revisión narrativa Analysis of the veracity of certain beliefs frequently associated to resistance training. A narrative review Prince Sultan University (Arabia Saudí) Resumen. El objetivo del estudio fue contrastar la veracidad de las siguientes creencias:1-El entrenamiento de fuerza y resistencia es incompatible. 2-El entrenamiento de fuerza limita la flexibilidad. 3-Las rutinas divididas son más eficaces que las de cuerpo entero. 4-El entrenamiento de fuerza no es útil para la pérdida de peso, o la mejora de la composición corporal. Se realizó una búsqueda en las siguientes bases de datos: ProQuest, Google Scholar, Scopus, ScienceDirect y Web of Science. Los criterios de selección fueron: a) Artículos escritos en Español o en Inglés. b) Investigaciones primarias con metodología experimental o cuasi-experimental. c) Escritos entre el año 2015 y 2019, salvo para los apartados 2 y 3, que se amplió hasta 2000 y 1990 respectivamente, debido a la escasez de publicaciones. d) La población objeto de estudio fueron adultos sanos que no practicaban deporte a nivel profesional o semiprofesional. e) Artículos que recogen exclusivamente adaptaciones logradas mediante una intervención con entrenamiento. Analizados los estudios, se pudo determinar que en adultos sanos: 1-El entrenamiento de fuerza y resistencia es compatible. 2-El entrenamiento de fuerza no deteriora la flexibilidad, y podría incluso mejorarla. 3-En virtud de los estudios existente, las rutinas divididas y las de cuerpo entero son igualmente eficaces para incrementar la fuerza. Las rutinas de cuerpo entero podrían generar mayor hipertrofia muscular. 4-El entrenamiento de fuerza es eficaz en la mejora de la composición corporal, y podría tener un impacto positivo en biomarcadores cardiovasculares y metabólicos. Palabras clave: Entrenamiento concurrente, resistencia, flexibilidad, fuerza. Abstract. The purpose of the study was to verify the veracity of the following beliefs: 1-Resistance and endurance training are incompatible. 2-Resistance training reduces flexibility. 3-Split body routines are more effective than full-body routines. 4-Resistance training is not useful neither in weight loss programs, nor to change body composition. The following databases were searched: ProQuest, Google Scholar, Scopus, ScienceDirect and Web of Science. The selection criteria were: a) Articles written in Spanish or in English b) Primary research following an experimental or quasi-experimental methodology c) Written between 2015 and 2019, except for section 2 and 3, which was extended until 2000 and 1990 respectively, due to the shortage of publications d) The target population of study were healthy adults who did not practice sports at the professional or semi-professional level e) Papers which include only adaptations achieved through training interventions. Once the studies were analyzed, it was concluded that in healthy adults: 1-The combination of resistance and endurance training is compatible. 2-Strength training does not decrease flexibility, and it could even improve it. 3-On the basis of existing studies, split and full-body routines are equally effective in improving strength. Full-body routines could generate higher muscle hypertrophy. 4-Strength training is effective in improving body composition, and could make a positive impact on cardiovascular and metabolic biomarkers.
... Συγκεκριμένα, στην έρευνα του Beattie και συν. (9) καταδεικνύονται τα πλεονεκτήματα ορισμένων μορφών προπόνησης δύναμης που εφαρμόστηκαν κατά τη διάρκεια 40 εβδομάδων με την περιοδική μέθοδο (63). Ωστόσο είναι απαραίτητη η εκπόνηση περισσότερων ερευνών σε ό,τι αφορά μακροπρόθεσμα την αποτελεσματικότητα της εν λόγω μεθόδου περιοδικότητας στους δρομείς αντοχής. ...
Research has shown that, concurrent strength and endurance training has been considered an effective method to improve running economy (RE) and performance in endurance running athletes. Strength training improves the RE 2% -8%, making the runner consume less O2 for the same submaximal running velocity. This improvement was due to neural adaptations without observable muscle hypertrophy. However, no improvements were found in relative VO2max, when strength training was performed in conjunction with aerobic training. The purpose of this narrative review is to examine various strength training programs that have attempted to improve RE. More specifically, the effect of a) resistance training programs, aiming to improve Maximal Force, such as heavy weight training, isometric training and vibration training with heavy weight, and b) explosive training, aiming to improve Maximal Power, such as low-middle intensity resistors with explosive repetitions, plyometric training or a combination of the two above, was investigated.Complex training was also investigated. The results showed that heavy weight training and explosive training are effective concurrent training methods aiming to improve RE. In particular, improved lower-limb coordination, muscle coactivation and increased muscle stiffness, which enhances the ability of the muscles to store and utilize elastic energy more efficiently, result in reduced energy expenditure. Similarly, other neuromuscular adaptations such as vertical jump (5J) and contact time correlated with the speed in the anaerobic threshold which was associated with improved RE and running performance. The different magnitude of improvement of the RE for each specific type of strength training, probably, due to the different characteristics of the exercise protocols and trainees. Therefore, more research is needed to determine which style of strength training is more beneficial than any other. Furthermore, future studies should examine movement-specific forms of resistance training.
... These neuromuscular adaptations may allow runners to maintain a constant running velocity with a relative low energy cost (Blagrove et al., 2018). In addition, any PAP effects induced by a plyometric warm-up may potentiate the recruitment of type I muscle fibers, thereby postponing the activation of less efficient type II muscle fibers and reducing energy consumption during running (Schumann et al., 2016). Moreover, elastic energy induced by a plyometric warm-up can be stored in the tendons and skeletal muscles, making an extensive contribution to propulsion (Anderson, 1996). ...
This study explored the impact of two differing warm-up protocols (involving either resistance exercises or plyometric exercises) on running economy (RE) in healthy recreationally active participants. Twelve healthy university students [three males, nine females, age 20 ± 2 years, maximal oxygen uptake (38.4 ± 6.4 ml min–1 kg–1)] who performed less than 5 h per week of endurance exercise volunteered to participant in this study. All participants completed three different warm-up protocols (control, plyometric, and resistance warm-up) in a counterbalanced crossover design with trials separated by 48 h, using a Latin-square arrangement. Dependent variables measured in this study were RE at four running velocities (7, 8, 9, and 10 km h–1), maximal oxygen uptake; heart rate; respiratory exchange rate; expired ventilation; perceived race readiness; rating of perceived exertion, time to exhaustion and leg stiffness. The primary finding of this study was that the plyometric warm-up improved RE compared to the control warm-up (6.2% at 7 km h–1, ES = 0.355, 9.1% at 8 km h–1, ES = 0.513, 4.5% at 9 km h–1, ES = 0.346, and 4.4% at 10 km h–1, ES = 0.463). There was no statistically significant difference in VO2 between control and resistance warm-up conditions at any velocity. There were also no statistically significant differences between conditions in other metabolic and pulmonary gas exchange variables; time to exhaustion; perceived race readiness and maximal oxygen uptake. However, leg stiffness increased by 20% (P = 0.039, ES = 0.90) following the plyometric warm-up and was correlated with the improved RE at a velocity of 8 km h–1 (r = 0.475, P = 0.041). No significant differences in RE were found between the control and resistance warm-up protocols. In comparison with the control warm-up protocol, an acute plyometric warm-up protocol can improve RE in healthy adults.
... Initially, the main aim of the training prescription was to improve aerobic fitness. However, the aerobic running training led to a systematic reduction in muscle strength by 10-15 kg, as was previously shown in healthy recreational endurance athletes [21]. The lowest values of muscle strength were recorded from August 2018 to February 2019, and correspond well with the lowest score of "physical functioning". ...
Background:
Primary Ciliary Dyskinesia (PCD) is an autosomal recessive disease, characterized by ciliary dysfunction and impaired mucociliary clearance. Previous studies have indicated a low physical fitness in PCD patients but currently it is not known whether physical training beneficially affects fitness, inflammatory markers and quality of life.
Case presentation:
The patient was a Caucasian male (67.0 kg, 183.3 cm), born in 1984 and was diagnosed with the Kartagener Syndrome (i.e. PCD) right after birth. He was prescribed structured physical training over a period of almost two years (from August 2017-June 2019) and was assessed regularly. Aerobic fitness improved throughout the intervention period, but no systematic changes were observed in inflammatory markers and overall quality of life.
Conclusions:
Our data provides reasoning to stress the implementation of structured physical training to enhance physical performance also in the management of PCD.
... The extent of adaptation induced by concurrent training is highly dependent on the interaction between resistance and endurance training sessions [72,73]. Thus, the sequence of resistance and endurance training session may be critical for optimising endurance development given that the acute physiological responses are distinct between each mode of exercise [15]. ...
Whilst the “acute hypothesis” was originally coined to describe the detrimental effects of concurrent training on strength development, similar physiological processes may occur when endurance training adaptations are compromised. There is a growing body of research indicating that typical resistance exercises impair neuromuscular function and endurance performance during periods of resistance training-induced muscle damage. Furthermore, recent evidence suggests that the attenuating effects of resistance training-induced muscle damage on endurance performance are influenced by exercise intensity, exercise mode, exercise sequence, recovery and contraction velocity of resistance training. By understanding the influence that training variables have on the level of resistance training-induced muscle damage and its subsequent attenuating effects on endurance performance, concurrent training programs could be prescribed in such a way that minimises fatigue between modes of training and optimises the quality of endurance training sessions. Therefore, this review will provide considerations for concurrent training prescription for endurance development based on scientific evidence. Furthermore, recommendations will be provided for future research by identifying training variables that may impact on endurance development as a result of concurrent training.
... There has been a growth in the literature investigating the compatibility of strength and aerobic training (i.e. concurrent training) and the effect on the mechanisms underpinning protein synthesis [36,37]. Therefore, it is important that coaches are aware of this potential 'interference effect' associated with combined strength and endurance training. ...
Exercise economy, \( \dot{\mathrm{V}}{\mathrm{O}}_{2\max } \) and sprinting ability play a vital role in elite distance running performance. Research has shown that the neuromuscular adaptations from strength training can improve these key performance indicators. Therefore, the purpose of this chapter is to discuss the importance of prescribing strength (maximal-, explosive- and reactive-strength) and speed training (technical drills and maximum-velocity sprinting) for long-term neuromuscular development.
Background
Running economy is defined as the energy demand at submaximal running speed, a key determinant of overall running performance. Strength training can improve running economy, although the magnitude of its effect may depend on factors such as the strength training method and the speed at which running economy is assessed.
Aim
To compare the effect of different strength training methods (e.g., high loads, plyometric, combined methods) on the running economy in middle- and long-distance runners, over different running speeds, through a systematic review with meta-analysis.
Methods
A systematic search was conducted across several electronic databases including Web of Science, PubMed, SPORTDiscus, and SCOPUS. Using different keywords and Boolean operators for the search, all articles indexed up to November 2022 were considered for inclusion. In addition, the PICOS criteria were applied: Population: middle- and long-distance runners, without restriction on sex or training/competitive level; Intervention: application of a strength training method for ≥ 3 weeks (i.e., high loads (≥ 80% of one repetition maximum); submaximal loads [40–79% of one repetition maximum); plyometric; isometric; combined methods (i.e., two or more methods); Comparator: control group that performed endurance running training but did not receive strength training or received it with low loads (< 40% of one repetition maximum); Outcome: running economy, measured before and after a strength training intervention programme; Study design: randomized and non-randomized controlled studies. Certainty of evidence was assessed with the GRADE approach. A three-level random-effects meta-analysis and moderator analysis were performed using R software (version 4.2.1).
Results
The certainty of the evidence was found to be moderate for high load training, submaximal load training, plyometric training and isometric training methods and low for combined methods. The studies included 195 moderately trained, 272 well trained, and 185 highly trained athletes. The strength training programmes were between 6 and 24 weeks’ duration, with one to four sessions executed per week. The high load and combined methods induced small (ES = − 0.266, p = 0.039) and moderate (ES = − 0.426, p = 0.018) improvements in running economy at speeds from 8.64 to 17.85 km/h and 10.00 to 14.45 km/h, respectively. Plyometric training improved running economy at speeds ≤ 12.00 km/h (small effect, ES = − 0.307, p = 0.028, β1 = 0.470, p = 0.017). Compared to control groups, no improvement in running economy (assessed speed: 10.00 to 15.28 and 9.75 to 16.00 km/h, respectively) was noted after either submaximal or isometric strength training (all, p > 0.131). The moderator analyses showed that running speed (β1 = − 0.117, p = 0.027) and VO2max (β1 = − 0.040, p = 0.020) modulated the effect of high load strength training on running economy (i.e., greater improvements at higher speeds and higher VO2max).
Conclusions
Compared to a control condition, strength training with high loads, plyometric training, and a combination of strength training methods may improve running economy in middle- and long-distance runners. Other methods such as submaximal load training and isometric strength training seem less effective to improve running economy in this population. Of note, the data derived from this systematic review suggest that although both high load training and plyometric training may improve running economy, plyometric training might be effective at lower speeds (i.e., ≤ 12.00 km/h) and high load strength training might be particularly effective in improving running economy (i) in athletes with a high VO2max, and (ii) at high running speeds.
Protocol Registration
The original protocol was registered (https://osf.io/gyeku) at the Open Science Framework.
Background
As an adjunct to running training, heavy resistance and plyometric training have recently drawn attention as potential training modalities that improve running economy and running time trial performance. However, the comparative effectiveness is unknown. The present systematic review and meta-analysis aimed to determine if there are different effects of heavy resistance training versus plyometric training as an adjunct to running training on running economy and running time trial performance in long-distance runners.
Methods
Electronic databases of PubMed, Web of Science, and SPORTDiscus were searched. Twenty-two studies completely satisfied the selection criteria. Data on running economy and running time trial performance were extracted for the meta-analysis. Subgroup analyses were performed with selected potential moderators.
Results
The pooled effect size for running economy in heavy resistance training was greater ( g = − 0.32 [95% confidence intervals [CIs] − 0.55 to − 0.10]: effect size = small) than that in plyometric training ( g = -0.13 [95% CIs − 0.47 to 0.21]: trivial). The effect on running time trial performance was also larger in heavy resistance training ( g = − 0.24 [95% CIs − 1.04 to − 0.55]: small) than that in plyometric training ( g = − 0.17 [95% CIs − 0.27 to − 0.06]: trivial). Heavy resistance training with nearly maximal loads (≥ 90% of 1 repetition maximum [1RM], g = − 0.31 [95% CIs − 0.61 to − 0.02]: small) provided greater effects than those with lower loads (< 90% 1RM, g = − 0.17 [95% CIs − 1.05 to 0.70]: trivial). Greater effects were evident when training was performed for a longer period in both heavy resistance (10–14 weeks, g = − 0.45 [95% CIs − 0.83 to − 0.08]: small vs. 6–8 weeks, g = − 0.21 [95% CIs − 0.56 to 0.15]: small) and plyometric training (8–10 weeks, g = 0.26 [95% CIs − 0.67 to 0.15]: small vs. 4–6 weeks, g = − 0.06 [95% CIs 0.67 to 0.55]: trivial).
Conclusions
Heavy resistance training, especially with nearly maximal loads, may be superior to plyometric training in improving running economy and running time trial performance. In addition, running economy appears to be improved better when training is performed for a longer period in both heavy resistance and plyometric training.
[Main text in Slovene]. The most important predictors of performance in endurance sports are maximal oxygen uptake, the second lactate threshold or critical power and movement efficiency. For a long time it was believed that resistance training is not suitable for endurance athletes due to unwanted increases in muscle mass and training of muscle fibres that are not important for those athletes. Based on the literature review that we performed we conclude that resistance training positively affects numerous important determinants of endurance performance and that there are no downsides reported. Studies report that addition of resistance training can have possitive effects as only as 8 weeks after the onset of such training. Resistance training can thus very effectively contribute towards better performance provided that exercise is designed according to the needs of a discipline and the athlete. The main reasons for efficacy of resistance training appears to be improved movement efficiency, maximal locomotion speed, improvements of anaerobic capacity and concomitant delayed onset of fatigue.
Concurrent training, defined as resistance training sessions programmed alongside endurance training sessions during the same cycle, is a tool that highly trained runners can use to augment performance. A review of the current literature explains how resistance training focused on increasing maximal force development and power output can improve running economy, a key performance indicator for endurance running. This review explains the current concepts in concurrent training for competitive distance runners, discusses misconceptions related to concurrent training, and offers practical implementation examples for coaches, athletes, and strength and conditioning practitioners working with this special population.
Background:
Recently, much attention has been paid to the role of neuromuscular function in long-distance running performance. Complex Training (CT) is a combination training method that alternates between performing heavy resistance exercises and plyometric exercises within one single session, resulting in great improvement in neuromuscular adaptation. The purpose of this study was to compare the effect of CT vs. heavy resistance training (HRT) on strength and power indicators, running economy (RE), and 5-km performance in well-trained male distance runners.
Methods:
Twenty-eight well-trained male distance runners (19-23 years old, VO2max:65.78 ± 4.99 ml.kg-1.min-1) performed one pre-test consisting of: maximum strength (1RM), counter movement jump (CMJ) height, peak power, a drop jump (DJ), and RE assessments, and blood lactate concentration (BLa) measurement at the speeds from 12-16 km.h-1, a 50-m sprint, and a 5-km running performance test. They were then divided into 3 groups: complex training group (CT, n = 10), that performed complex training and endurance training; heavy resistance training group (HRT, n = 9) that performed heavy strength training and endurance training; and control group (CON, n = 9) that performed strength-endurance training and endurance training. After the 8 weeks training intervention, all participants completed a post-test to investigate the training effects on the parameters measured.
Results:
After training intervention, both the CT and HRT groups had improvements in: 1RM strength (16.88%, p < 0.001; 18.80%, p < 0.001, respectively), CMJ height (11.28%, p < 0.001; 8.96%, p < 0.001, respectively), 14 km.h-1RE (-7.68%, p < 0.001; -4.89%, p = 0.009, respectively), 50-m sprints (-2.26%, p = 0.003; -2.14%, p = 0.007, respectively) and 5-km running performance (-2.80%, p < 0.001; -2.09%, p < 0.001, respectively). The CON group did not show these improvements. All three training groups showed improvement in the 12 km.h-1RE (p ≤ 0.01). Only the CT group exhibited increases in DJ height (12.94%, p < 0.001), reactive strength index (19.99%, p < 0.001), 16 km.h-1 RE (-7.38%, p < 0.001), and a reduction of BLa concentrations at the speed of 16 km.h-1 (-40.80%, p < 0.001) between pre- and post-tests.
Conclusion:
This study demonstrated that CT can enhance 1RM strength, CMJ height, 12 and 14 km.h-1REs, 50-m sprints and 5-km running performances in well-trained male distance runners and may be superior to HRT for the development of reactive strength and 16 km.h-1RE, and reduction of BLa concentrations at speed of 16 km.h-1. Young male distance runners could integrate CT into their programs to improve the running performance.
Research Review to Finnish Sport Policy Report. Read more:
http://www.liikuntaneuvosto.fi/files/613/tutkimuskatsaus_liikuntapoliittiseen_selontekoon_2018-4-digi.pdf
THE PURPOSE OF THIS REVIEW IS TWOFOLD: TO ELUCIDATE THE UTILITY OF RESISTANCE TRAINING FOR ENDURANCE ATHLETES, AND PROVIDE THE PRACTITIONER WITH EVIDENCED-BASED PERIODIZATION STRATEGIES FOR CONCURRENT STRENGTH AND ENDURANCE TRAINING IN ATHLETIC POPULATIONS. BOTH LOW-INTENSITY EXERCISE ENDURANCE (LIEE) AND HIGH-INTENSITY EXERCISE ENDURANCE (HIEE) HAVE BEEN SHOWN TO IMPROVE AS A RESULT OF MAXIMAL, HIGH FORCE, LOW VELOCITY (HFLV) AND EXPLOSIVE, LOW-FORCE, HIGH-VELOCITY STRENGTH TRAINING. HFLV STRENGTH TRAINING IS RECOMMENDED INITIALLY TO DEVELOP A NEUROMUSCULAR BASE FOR ENDURANCE ATHLETES WITH LIMITED STRENGTH TRAINING EXPERIENCE. A SEQUENCED APPROACH TO STRENGTH TRAINING INVOLVING PHASES OF STRENGTH-ENDURANCE, BASIC STRENGTH, STRENGTH, AND POWER WILL PROVIDE FURTHER ENHANCEMENTS IN LIEE AND HIEE FOR HIGH-LEVEL ENDURANCE ATHLETES.
The molecular signaling of mitochondrial biogenesis is enhanced when resistance exercise is added to a bout of endurance exercise. The purpose of the present study was to examine if this mode of concurrent training translates into increased mitochondrial content and improved endurance performance. Moderately trained cyclists performed 8 weeks (two sessions per week) of endurance training only (E, n = 10; 60-min cycling) or endurance training followed by strength training (ES, n = 9; 60-min cycling + leg press). Muscle biopsies were obtained before and after the training period and analyzed for enzyme activities and protein content. Only the ES group increased in leg strength (+19%, P < 0.01), sprint peak power (+5%, P < 0.05), and short-term endurance (+9%, P < 0.01). In contrast, only the E group increased in muscle citrate synthase activity (+11%, P = 0.06), lactate threshold intensity (+3%, P < 0.05), and long-term endurance performance (+4%, P < 0.05). Content of mitochondrial proteins and cycling economy was not affected by training. Contrary to our hypothesis, the results demonstrate that concurrent training does not enhance muscle aerobic capacity and endurance performance in cyclists.
This study investigated the effects of endurance training only (E, n = 14) and same-session combined training, when strength training is repeatedly preceded by endurance loading (endurance and strength training (E+S), n = 13) on endurance (1000-m running time during incremental field test) and strength performance (1-repetition maximum (1RM) in dynamic leg press), basal serum hormone concentrations, and endurance loading-induced force and hormone responses in recreationally endurance-trained men. E was identical in the 2 groups and consisted of steady-state and interval running, 4-6 times per week for 24 weeks. E+S performed additional mixed-maximal and explosive-strength training (2 times per week) immediately following an incremental running session (35-45 min, 65%-85% maximal heart rate). E and E+S decreased running time at week 12 (-8% ± 5%, p = 0.001 and -7% ± 3%, p < 0.001) and 24 (-13% ± 5%, p < 0.001 and -9% ± 5%, p = 0.001). Strength performance decreased in E at week 24 (-5% ± 5%, p = 0.014) but was maintained in E+S (between-groups at week 12 and 24, p = 0.014 and 0.011, respectively). Basal serum testosterone and cortisol concentrations remained unaltered in E and E+S but testosterone/sex hormone binding globulin ratio decreased in E+S at week 12 (-19% ± 26%, p = 0.006). At week 0 and 24, endurance loading-induced acute force (-5% to -9%, p = 0.032 to 0.001) and testosterone and cortisol responses (18%-47%, p = 0.013 to p < 0.001) were similar between E and E+S. This study showed no endurance performance benefits when strength training was performed repeatedly after endurance training compared with endurance training only. This was supported by similar acute responses in force and hormonal measures immediately post-endurance loading after the training with sustained 1RM strength in E+S.
Endurance can be defined as the ability to maintain or to repeat a given force or power output. The sport performance-endurance relationship is a multi-factorial concept. However, evidence indicates that maximum strength is a major component. Conceptually, endurance is a continuum. The literature indicates that (a) maximum strength is moderately to strongly related to endurance capabilities and associated factors, a relationship that is likely stronger for high intensity exercise endurance (HIEE) activities than for low intensity exercise endurance (LIEE); (b) strength training can increase both HIEE and LIEE, the effect being greater for HIEE; (c) the volume of strength training plays a role in endurance adaptation; and (d) mechanical specificity and training program variables also play a role in the degree of adaptation.
Economy, velocity/power at maximal oxygen uptake ([Formula: see text]) and endurance-specific muscle power tests (i.e. maximal anaerobic running velocity; vMART), are now thought to be the best performance predictors in elite endurance athletes. In addition to cardiovascular function, these key performance indicators are believed to be partly dictated by the neuromuscular system. One technique to improve neuromuscular efficiency in athletes is through strength training.
The aim of this systematic review was to search the body of scientific literature for original research investigating the effect of strength training on performance indicators in well-trained endurance athletes-specifically economy, [Formula: see text] and muscle power (vMART).
A search was performed using the MEDLINE, PubMed, ScienceDirect, SPORTDiscus and Web of Science search engines. Twenty-six studies met the inclusion criteria (athletes had to be trained endurance athletes with ≥6 months endurance training, training ≥6 h per week OR [Formula: see text] ≥50 mL/min/kg, the strength interventions had to be ≥5 weeks in duration, and control groups used). All studies were reviewed using the PEDro scale.
The results showed that strength training improved time-trial performance, economy, [Formula: see text] and vMART in competitive endurance athletes.
The present research available supports the addition of strength training in an endurance athlete's programme for improved economy, [Formula: see text], muscle power and performance. However, it is evident that further research is needed. Future investigations should include valid strength assessments (i.e. squats, jump squats, drop jumps) through a range of velocities (maximal-strength ↔ strength-speed ↔ speed-strength ↔ reactive-strength), and administer appropriate strength programmes (exercise, load and velocity prescription) over a long-term intervention period (>6 months) for optimal transfer to performance.
The well-established central deficit in ultra-endurance running races is not understood. The use of transcranial magnetic stimulation (TMS) in parallel with peripheral nerve stimulation provides insight into the source of these central changes. The aims of this study were to determine the presence and magnitude of voluntary activation deficits, especially supraspinal deficits, after a mountain trail-running race and whether this can be explained by simultaneous changes in corticospinal excitability and intracortical inhibition.
Neuromuscular function (TMS and femoral nerve electrical stimulation) of the knee extensors was evaluated before and after a 110-km ultra-trail in 25 experienced ultra-endurance trail runners during maximal and submaximal voluntary contractions and in relaxed muscle.
Voluntary activation assessed by both femoral nerve electrical stimulation (-26%) and TMS (-16%) decreased and were correlated (P < 0.01). Decreases in potentiated twitch and doublet amplitudes were correlated with decreased voluntary activation assessed by TMS (P < 0.05). There was increased motor-evoked potential (MEP) amplitude (P < 0.05) without change in cortical silent period (CSP) elicited by TMS at optimal stimulus intensity. Conversely, CSP at sub-optimal TMS intensity increased (P < 0.05) without concurrent change in MEP amplitude.
The present results demonstrate the development of a large central activation deficit assessed by TMS indicating that cortical motoneurons are severely impaired in their ability to fire at optimal frequency or be fully recruited following an ultra-endurance running race. MEP and CSP responses suggest a shift in the sigmoidal MEP-stimulus-intensity relationship towards larger MEPs at higher TMS intensity without change in inflection point of the curve and a left-shift in the CSP-stimulus-intensity relationship.
Here we report on the effect of combining endurance training with heavy or explosive strength training on endurance performance in endurance-trained runners and cyclists. Running economy is improved by performing combined endurance training with either heavy or explosive strength training. However, heavy strength training is recommended for improving cycling economy. Equivocal findings exist regarding the effects on power output or velocity at the lactate threshold. Concurrent endurance and heavy strength training can increase running speed and power output at VO2max (Vmax and Wmax , respectively) or time to exhaustion at Vmax and Wmax . Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used. It is suggested that the improved endurance performance may relate to delayed activation of less efficient type II fibers, improved neuromuscular efficiency, conversion of fast-twitch type IIX fibers into more fatigue-resistant type IIA fibers, or improved musculo-tendinous stiffness.
The aim of this study was investigate the effects of different intrasession exercise orders in the neuromuscular adaptations induced by concurrent training in elderly. Twenty-six healthy elderly men (64.7 ± 4.1 years), were placed into two concurrent training groups: strength prior to (SE, n = 13) or after (ES, n = 13) endurance training. Subjects trained strength and endurance training during 12 weeks, three times per week performing both exercise types in the same training session. Upper and lower body one maximum repetition test (1RM) and lower-body isometric peak torque (PTiso) and rate of force development were evaluated as strength parameters. Upper and lower body muscle thickness (MT) was determined by ultrasonography. Lower-body maximal surface electromyographic activity of vastus lateralis and rectus femoris muscles (maximal electromyographic (EMG) amplitude) and neuromuscular economy (normalized EMG at 50 % of pretraining PTiso) were determined. Both SE and ES groups increased the upper- and lower-body 1RM, but the lower-body 1RM increases observed in the SE was higher than ES (35.1 ± 12.8 vs. 21.9 ± 10.6 %, respectively; P < 0.01). Both SE and ES showed MT increases in all muscles evaluated, with no differences between groups. In addition, there were increases in the maximal EMG and neuromuscular economy of vastus lateralis in both SE and ES, but the neuromuscular economy of rectus femoris was improved only in SE (P < 0.001). Performing strength prior to endurance exercise during concurrent training resulted in greater lower-body strength gains as well as greater changes in the neuromuscular economy (rectus femoris) in elderly.
The aim of the present study was to examine the effect of in-season strength maintenance training frequency on strength, jump height, and 40-m sprint performance in professional soccer players. The players performed the same strength training program twice a week during a 10-week preparatory period. In-season, one group of players performed 1 strength maintenance training session per week (group 2 + 1; n = 7), whereas the other group performed 1 session every second week (group 2 + 0.5; n = 7). Only the strength training frequency during the in-season differed between the groups, whereas the exercise, sets and number of repetition maximum as well as soccer sessions were similar in the 2 groups. The preseason strength training resulted in an increased strength, sprint, and jump height (p < 0.05). During the first 12 weeks of the in-season, the initial gain in strength and 40-m sprint performance was maintained in group 2 + 1, whereas both strength and sprint performance were reduced in group 2 + 0.5 (p < 0.05). There was no statistical significant change in jump height in any of the 2 groups during the first 12 weeks of the in-season. In conclusion, performing 1 weekly strength maintenance session during the first 12 weeks of the in-season allowed professional soccer players to maintain the improved strength, sprint, and jump performance achieved during a preceding 10-week preparatory period. On the other hand, performing only 1 strength maintenance session every second week during the in-season resulted in reduced leg strength and 40-m sprint performance. The practical recommendation from the present study is that during a 12-week period, 1 strength maintenance session per week may be sufficient to maintain initial gain in strength and sprint performance achieved during a preceding preparatory period.
This study examined effects of periodized maximal versus explosive strength training and reduced strength training, combined with endurance training, on neuromuscular and endurance performance in recreational endurance runners. Subjects first completed 6 weeks of preparatory strength training. Then, groups of maximal strength (MAX, n=11), explosive strength (EXP, n=10) and circuit training (C, n=7) completed an 8-week strength training intervention, followed by 14 weeks of reduced strength training. Maximal strength (1RM) and muscle activation (EMG) of leg extensors, countermovement jump (CMJ), maximal oxygen uptake (VO(2MAX)), velocity at VO(2MAX) (vVO(2MAX)) running economy (RE) and basal serum hormones were measured. 1RM and CMJ improved (p<0.05) in all groups accompanied by increased EMG in MAX and EXP (p<0.05) during strength training. Minor changes occurred in VO(2MAX), but vVO(2MAX) improved in all groups (p<0.05) and RE in EXP (p<0.05). During reduced strength training 1RM and EMG decreased in MAX (p<0.05) while vVO(2MAX) in MAX and EXP (p<0.05) and RE in MAX (p<0.01) improved. Serum testosterone and cortisol remained unaltered. Maximal or explosive strength training performed concurrently with endurance training was more effective in improving strength and neuromuscular performance and in enhancing vVO (2MAX) and RE in recreational endurance runners than concurrent circuit and endurance training.
The purpose of this study was to investigate the effect of heavy strength training on thigh muscle cross-sectional area (CSA), determinants of cycling performance, and cycling performance in well-trained cyclists. Twenty well-trained cyclists were assigned to either usual endurance training combined with heavy strength training [E + S; n = 11 (male symbol = 11)] or to usual endurance training only [E; n = 9 (male symbol = 7, female symbol = 2)]. The strength training performed by E + S consisted of four lower body exercises [3 x 4-10 repetition maximum (RM)], which were performed twice a week for 12 weeks. Thigh muscle CSA, maximal force in isometric half squat, power output in 30 s Wingate test, maximal oxygen consumption (VO(2max)), power output at 2 mmol l(-1) blood lactate concentration ([la(-)]), and performance, as mean power production, in a 40-min all-out trial were measured before and after the intervention. E + S increased thigh muscle CSA, maximal isometric force, and peak power in the Wingate test more than E. Power output at 2 mmol l(-1) [la(-)] and mean power output in the 40-min all-out trial were improved in E + S (P < 0.05). For E, only performance in the 40-min all-out trial tended to improve (P = 0.057). The two groups showed similar increases in VO(2max) (P < 0.05). In conclusion, adding strength training to usual endurance training improved determinants of cycling performance as well as performance in well-trained cyclists. Of particular note is that the added strength training increased thigh muscle CSA without causing an increase in body mass.
The purpose of the present study was to investigate the effect of maximal strength training on cycling economy (CE) at 70% of maximal oxygen consumption (Vo2max), work efficiency in cycling at 70% Vo2max, and time to exhaustion at maximal aerobic power. Responses in 1 repetition maximum (1RM) and rate of force development (RFD) in half-squats, Vo2max, CE, work efficiency, and time to exhaustion at maximal aerobic power were examined. Sixteen competitive road cyclists (12 men and 4 women) were randomly assigned into either an intervention or a control group. Thirteen (10 men and 3 women) cyclists completed the study. The intervention group (7 men and 1 woman) performed half-squats, 4 sets of 4 repetitions maximum, 3 times per week for 8 weeks, as a supplement to their normal endurance training. The control group continued their normal endurance training during the same period. The intervention manifested significant (p < 0.05) improvements in 1RM (14.2%), RFD (16.7%), CE (4.8%), work efficiency (4.7%), and time to exhaustion at pre-intervention maximal aerobic power (17.2%). No changes were found in Vo2max or body weight. The control group exhibited an improvement in work efficiency (1.4%), but this improvement was significantly (p < 0.05) smaller than that in the intervention group. No changes from pre- to postvalues in any of the other parameters were apparent in the control group. In conclusion, maximal strength training for 8 weeks improved CE and efficiency and increased time to exhaustion at maximal aerobic power among competitive road cyclists, without change in maximal oxygen uptake, cadence, or body weight. Based on the results from the present study, we advise cyclists to include maximal strength training in their training programs.
The purpose of this study was to examine the reliability and validity of the "panoramic" brightness mode ultrasonography (US) method to detect training-induced changes in muscle cross-sectional area (CSA) by comparison with results obtained using magnetic resonance imaging (MRI). Out of 27 young male volunteers, 20 subjects were assigned to training group and seven to non-training control group. Muscle CSAs of vastus lateralis were analyzed by MRI and US before and after 21 weeks of either heavy resistance training or control period. Measured by both the US and MRI, the resistance training induced significant increases (~13-14%, P < 0.001) in muscle CSA, whereas no changes were observed in control group. A high repeatability was found between the two consequent US measurements (intraclass correlation coefficient, ICC of 0.997) with standard error of measurement (SEM) of 0.38 cm(2) and smallest detectable difference of 1.1 cm(2). Validity of the US method against MRI in assessing CSA of VL produced ICC of 0.905 and SEM of 0.87 cm(2) with high limits of agreement analyzed by Bland and Altman method. However, the MRI produced systematically (10 +/- 4%, P < 0.01) larger CSA values than the US method. The US showed high agreement against MRI in detecting changes in muscle CSA (ICC of 0.929, SEM of 0.94 cm(2)). The results of this study showed that the panoramic US method provides repeatable measures of a muscle CSA although MRI produced larger absolute CSA values. Moreover, this US method detects training-induced changes in muscle CSA with a comparable degree of precision to MRI.
To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics, 10 experimental (E) and 8 control (C) endurance athletes trained for 9 wk. The total training volume was kept the same in both groups, but 32% of training in E and 3% in C was replaced by explosive-type strength training. A 5-km time trial (5K), running economy (RE), maximal 20-m speed (V20 m), and 5-jump (5J) tests were measured on a track. Maximal anaerobic (MART) and aerobic treadmill running tests were used to determine maximal velocity in the MART (VMART) and maximal oxygen uptake (VO2 max). The 5K time, RE, and VMART improved (P < 0.05) in E, but no changes were observed in C. V20 m and 5J increased in E (P < 0.01) and decreased in C (P < 0.05). VO2 max increased in C (P < 0.05), but no changes were observed in E. In the pooled data, the changes in the 5K velocity during 9 wk of training correlated (P < 0.05) with the changes in RE [O2 uptake (r = -0.54)] and VMART (r = 0.55). In conclusion, the present simultaneous explosive-strength and endurance training improved the 5K time in well-trained endurance athletes without changes in their VO2 max. This improvement was due to improved neuromuscular characteristics that were transferred into improved VMART and running economy.
This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) performance in well-trained endurance athletes with different distance running capability. Nine high (HC) and ten low (LC) caliber endurance athletes performed the 10 K on a 200 m indoor track, constant velocity lap (CVL, 4.5 m x s(-1)) 5 times during the course of the 10 K and maximal 20 m speed test before (20 m(b)) and after (20 m(a)) the 10 K. Running velocity (V), ground contact times (CT), ground reaction forces (F) and electromyographic activity (EMG) of the leg muscles (vastus lateralis; VL, biceps femoris; BF, gastrocnemius; GA) were measured during 20 m(b), 20 m(a), and CVLs. The 10 K times differed (p<0.001) between HC and LC (36.3+/-1.2 and 39.2+/-2.0 min, respectively) but no differences were observed in 20 m(b) velocity. The 10 K led to significant (p<0.05) decreases in V, F and integrated EMG (IEMG) and increases in CTs of 20 m(a) in both groups. No changes were observed in HC or LC in F and IEMG during the CVLs but HC showed shorter (p<0.05) mean CT of CVLs than LC. A significant correlation (r = -0.56, p<0.05) was observed between the mean CT of CVLs and velocity of 10 K (V10K). Pre-activity of GA in relation to the IEMG of the total contact phase during the CVLs was higher (p<0.05) in HC than LC. The relative IEMGs of VL and GA in the propulsion phase compared to the IEMG of the 20 m(b) were lower (p<0.05) in HC than LC. In conclusion, marked fatigue took place in both HC and LC during the 10 K but the fatigue-induced changes in maximal 20 m run did not differentiate endurance athletes with different V10K. However, a capability to produce force rapidly throughout the 10 K accompanied with optimal preactivation and contact phase activation seem to be important for 10 km running performance in well trained endurance athletes.
Strength training is an important component in sports training and rehabilitation. Quantification of the dose-response relationships between training variables and the outcome is fundamental for the proper prescription of resistance training. The purpose of this comprehensive review was to identify dose-response relationships for the development of muscle hypertrophy by calculating the magnitudes and rates of increases in muscle cross-sectional area induced by varying levels of frequency, intensity and volume, as well as by different modes of strength training.
Computer searches in the databases MEDLINE, SportDiscus® and CJNAHL® were performed as well as hand searches of relevant journals, books and reference lists. The analysis was limited to the quadriceps femoris and the elbow flexors, since these were the only muscle groups that allowed for evaluations of dose-response trends. The modes of strength training were classified as dynamic external resistance (including free weights and weight machines), accommodating resistance (e.g. isokinetic and semi-isokinetic devices) and isometric resistance. The subcategories related to the types of muscle actions used. The results demonstrate that given sufficient frequency, intensity and volume of work, all three types of muscle actions can induce significant hypertrophy at an impressive rate and that, at present, there is insufficient evidence for the superiority of any mode and/or type of muscle action over other modes and types of training. Tentative dose-response relationships for each variable are outlined, based on the available evidence, and interactions between variables are discussed. In addition, recommendations for training and suggestions for further research are given.
The purpose of this study was to examine the influence of the sequence order of high-intensity endurance training and circuit training on changes in muscular strength and anaerobic power. Forty-eight physical education students (ages, 21.4 +/- 1.3 years) were assigned to 1 of 5 groups: no training controls (C, n = 9), endurance training (E, n = 10), circuit training (S, n = 9), endurance before circuit training in the same session, (E+S, n = 10), and circuit before endurance training in the same session (S+E, n = 10). Subjects performed 2 sessions per week for 12 weeks. Resistance-type circuit training targeted strength endurance (weeks 1-6) and explosive strength and power (weeks 7-12). Endurance training sessions included 5 repetitions run at the velocity associated with Vo2max (Vo2max) for a duration equal to 50% of the time to exhaustion at Vo2max; recovery was for an equal period at 60% Vo2max. Maximal strength in the half squat, strength endurance in the 1-leg half squat and hip extension, and explosive strength and power in a 5-jump test and countermovement jump were measured pre- and post-testing. No significant differences were shown following training between the S+E and E+S groups for all exercise tests. However, both S+E and E+S groups improved less than the S group in 1 repetition maximum (p < 0.01), right and left 1-leg half squat (p < 0.02), 5-jump test (p < 0.01), peak jumping force (p < 0.05), peak jumping power (p < 0.02), and peak jumping height (p < 0.05). The intrasession sequence did not influence the adaptive response of muscular strength and explosive strength and power. Circuit training alone induced strength and power improvements that were significantly greater than when resistance and endurance training were combined, irrespective of the intrasession sequencing.
To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics, 10 experimental (E) and 8 control (C) endurance athletes trained for 9 wk. The total training volume was kept the same in both groups, but 32% of training in E and 3% in C was replaced by explosive-type strength training. A 5-km time trial (5K), running economy (RE), maximal 20-m speed ( V 20 m ), and 5-jump (5J) tests were measured on a track. Maximal anaerobic (MART) and aerobic treadmill running tests were used to determine maximal velocity in the MART ( V MART ) and maximal oxygen uptake (V˙o 2 max ). The 5K time, RE, and V MART improved ( P < 0.05) in E, but no changes were observed in C. V 20 m and 5J increased in E ( P < 0.01) and decreased in C ( P < 0.05).V˙o 2 max increased in C ( P < 0.05), but no changes were observed in E. In the pooled data, the changes in the 5K velocity during 9 wk of training correlated ( P< 0.05) with the changes in RE [O 2 uptake ( r = −0.54)] and V MART ( r = 0.55). In conclusion, the present simultaneous explosive-strength and endurance training improved the 5K time in well-trained endurance athletes without changes in theirV˙o 2 max . This improvement was due to improved neuromuscular characteristics that were transferred into improved V MART and running economy.
The objective of this study was to examine the effects of high intensity exhaustive running exercise on the muscular torque capacity of the knee extensors for two types of contraction (concentric and eccentric) at different angular velocities (60 and 180°/s) in well-trained runners. Eleven male runners specialized in middle and long-distance running volunteered to participate in this study. Initially each subject performed, on different days, two familiarization sessions on an isokinetic dynamometer and an incremental treadmill test to volitional exhaustion to determine the velocity associated with the onset of blood lactate accumulation (OBLA). The subjects then returned to the laboratory on two occasions, separated by at least seven days, to perform maximal isokinetic knee contractions at each of the velocities under eccentric (Ecc) and concentric (Con) conditions. Conducted randomly, one test was performed after a standardized warm-up period of 5 min at 50% VO_2max. The other test was performed 15 min after continuous running at OBLA until volitional exhaustion. Following this high intensity exercise there was a significant reduction of Con at 60°/s and a significant reduction of Ecc at both velocities. Percent strength losses after running exercise were significantly different between contraction types only at 180°/s. We can conclude that the reduction in isokinetic peak torque of the knee extensors after a session of high intensity exhaustive running exercise at OBLA depends on the contraction type and angular velocity.
The present study investigated neuromuscular adaptations between same-session combined strength and endurance training with 2 loading orders and different day combined training over 24 weeks. 56 subjects were divided into different day (DD) combined strength and endurance training (4-6 d·wk-1) and same-session combined training: endurance preceding strength (E+S) or vice versa (S+E) (2-3 d·wk-1). Dynamic and isometric strength, EMG, voluntary activation, muscle cross-sectional area and endurance performance were measured. All groups increased dynamic one-repetition maximum (p<0.001; DD 13±7%, E+S 12±9% and S+E 17±12%) and isometric force (p<0.05-0.01), muscle cross-sectional area (p<0.001) and maximal power output during cycling (p<0.001). DD and S+E increased voluntary activation during training (p<0.05-0.01). In E+S no increase in voluntary activation was detected after 12 or 24 weeks. E+S also showed unchanged and S+E increased maximum EMG after 24 weeks during maximal isometric muscle actions. A high correlation (p<0.001, r=0.83) between the individual changes in voluntary activation and maximal knee extension force was found for E+S during weeks 13-24. Neural adaptations showed indications of being compromised and highly individual relating to changes in isometric strength when E+S-training was performed, while gains in one-repetition maximum, endurance performance and hypertrophy did not differ between the training modes.
Although the benefits of combined endurance (E) and strength (S) training for the development of physical fitness and health are well known, scientific examination of the effect of loading order when E and S are combined into the same training session (E+S vs. S+E) is rare. This study investigated the effects of moderate frequency E+S versus S+E training on physical fitness, body composition and blood lipids.
Physically active and healthy young men performed E+S (n=16) or S+E (n=18) training, 2-3 x·wk for 24 weeks. Endurance (by incremental bike test) and strength (by dynamic leg press) performance as well as body composition (by DXA), muscle cross-sectional area of vastus lateralis (by ultrasound) and blood lipids were determined before and after the intervention.
Time to exhaustion, aerobic power (W) and 1RM strength significantly increased in the two groups at week 24 (E+S 12-15%, p=0.003-0.001; S+E 16-17%, p<0.001) but no between-group difference was observed. Similarly, the two groups significantly increased total lean mass (E+S 3%, S+E 3%, both p=0.001) and muscle cross-sectional area (E+S 14%, p=0.001; S+E 16%, p<0.001) at week 24 to a similar extent. No significant changes in body fat or blood lipids were observed in either of the two groups at week 24.
These results showed that moderate frequency (2-3 x·wk) combined E+S or S+E training led to significant improvements in physical fitness and lean body mass but did not induce significant changes in body fat or blood lipids. Furthermore, as no between-group differences were observed, these results indicate that loading order does not seem to affect training adaptations of healthy moderately active young men.
The purpose of this study was to determine how different training modes would influence blood levels of growth hormone (hGH) and selected physiological parameters. Three training groups were established: LIFT, in which subjects trained with free weights and a Universal Gym three times per week with three sets at six to eight repetitions per lift (75 percent of one-repetition maximum) for 10 weeks; RUN, in which subjects ran at 75 percent of HR max three times per week; and COMBO, in which subjects underwent both LIFT and RUN training. Resting hGH levels were determined before and after training, and the hGH response to a single bout of exercise was determined at one, four, eight and 10 weeks. Each subject was tested for one-repetition (1 RM) strength in the bench and leg press during weeks one and 10 of training. Resting and exercise response blood samples were taken from an anticubital vein and centrifuged, and the serum was analyzed for hGH by radioimmunoassay techniques. The results of the hormonal measurements indicate that except for a significant (p < 0.05) decrease in the resting levels of hGH in the LIFT group, training did not alter hGH levels at rest. The 10 weeks of exercise training did not change the basic hGH response to a single bout of exercise in the LIFT and COMBO groups, but did shift the hGH peak of RUN subjects from four to eight minutes by the eighth week of training. The non-hormonal factors affected were: [latin capital V with dot above]O2 max of RUN and COMBO was significantly higher (p < 0.05) above LIFT; LBM and upper body strength of LIFT and COMBO was significantly elevated (p < 0.05) than RUN; and significant gains (p < 0.05) in lower body strength occurred only in LIFT, The data indicate that 10 weeks of exercise training does not significantly alter the basic hGH response to a single bout of exercise, but can influence the appearance of the hormonal peak. The results also show that a training program involving both running and lifting can produce the same gains in [latin capital V with dot above]O2 max and upper body strength as single-activity programs, but does not produce lower body strength gains.
(C) 1991 National Strength and Conditioning Association
Maximal strength training (MST) reduces pulmonary oxygen uptake (VO(2)) at a given submaximal exercise work rate (i.e. efficiency). However, whether the increase in efficiency originates in the trained skeletal muscle, and therefore the impact of this adaptation on muscle blood flow and arterial-venous oxygen difference (a-vO(2diff)), is unknown. Thus, five trained subjects partook in an 8 wk MST intervention consisting of half-squats with an emphasis on the rate of force development during the concentric phase of the movement. Pre- and post-training measurements of pulmonary VO(2) (indirect calorimetry), single leg blood flow (thermodilution), single leg a-vO(2diff) (blood gases) were performed, to allow the assessment of skeletal muscle VO(2) during submaximal cycling (237 ± 23 Watts; ~60% of their peak pulmonary VO(2) (VO(2peak))). Pulmonary VO(2peak) (~4.05 L/min) and peak work rate (~355 Watts), assessed during a graded exercise test, were unaffected by MST. As expected, following MST there was a significant reduction in pulmonary VO(2) during steady state submaximal cycling (~237 Watts: 3.2 ± 0.1 to 2.9 ± 0.1 L/min). This was accompanied by a significant reduction in single leg VO(2) (1,101 ± 105 to 935 ± 93 ml/min) and single leg blood flow (6,670 ± 700 to 5,649 ± 641ml/min), but no change in single leg a-vO(2diff) (16.7 ± 0.8 to 16.8 ± 0.4 ml/dl). These data confirm an MST-induced reduction in pulmonary VO(2) during submaximal exercise and identifies that this change in efficiency originates solely in skeletal muscle, reducing muscle blood flow, but not altering muscle a-vO(2diff).
This study investigated the effects of different intra-session exercise sequences in the cardiovascular and neuromuscular adaptations induced by concurrent training in elderly. Twenty-six healthy elderly men (64.7±4.1years), were randomly placed into two concurrent training groups: strength training prior to (SE, n=13) or after (ES, n=13) endurance training. Subjects trained strength and endurance training 3 times per week performing both exercise types in the same training session. The peak oxygen uptake (VO(2peak)), maximum aerobic workload (W(máx)), absolute (VT(1) and VT(2)) and relative (VT(1)% and VT(2)%) ventilatory thresholds, as well as workloads at VT(1) and VT(2) (W(VT1) and W(VT2)) were evaluated during a maximal incremental test on a cycle ergometer before and after the training. In addition, muscle quality (MQ) was evaluated by the quotient between maximal dynamic strength (one repetition maximum test) of the knee extensors and the quadriceps femoris muscle thickness determined by ultrasonography. There were no modifications after training in the VT(1), VT(2), VT(1)%, and VT(2)%. There was significant increase in the W(VT1) only in SE (P<0.05), as well as significant increase in the W(VT2) in both groups (P<0.001). There was significant increase in the VO(2peak), with both groups showing increases (P<0.001), with no difference between groups; as well significant increase in the W(máx) (P<0.001) with no difference between SE and ES. The force per unit of muscle mass of knee extensors increased in both groups (P<0.001), but the increase was significantly higher in SE than in ES (27.5±12.7 vs. 15.2±10.3%, P<0.02). Hence, the intra-session exercise sequence had no influence in the maximal endurance power adaptations to concurrent training, but had influence in the magnitude of the muscle quality enhancements.
Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO2max), cycling economy (CE) and long/short-term endurance capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P<0.01) but not E. VO2max remained unchanged. CE improved in E to reach values seen in SE. Short-term (5-min) endurance performance increased (3-4%) after SE and E (P<0.05), whereas 45-min endurance capacity increased (8%) with SE only (P<0.05). Type IIA fiber proportions increased and type IIX proportions decreased after SE training (P<0.05) with no change in E. Muscle fiber area and capillarization remained unchanged. In conclusion, concurrent strength/endurance training in young elite competitive cyclists led to an improved 45-min time-trial endurance capacity that was accompanied by an increased proportion of type IIA muscle fibers and gains in MVC and RFD, while capillarization remained unaffected.
This study investigated the effect of high-intensity endurance on subsequent isoinertial and isokinetic resistance exercise. One woman and five men (mean 6 SD: age 5 20.3 6 2.5 years; body mass 5 75.1 6 10.2 kg; height 5 177.8 6 10.3 cm) performed isoinertial and isokinetic resistance exercise under control conditions (no experimental intervention) and after an acute bout of high-intensity endurance exercise. Endurance exercise consisted of five 5-minute bouts of incremental cycle exercise at between 40 and 100% of peak cycle ergometer oxygen consumption (peak V˙ O2). Isoinertial resistance exercise consisted of three sets of squats with a load of 80% of one repetition maximum. Isokinetic resistance exercise consisted of five repetitions of leg extensions performed at five different contractile speeds (1.05, 2.09, 3.14, 4.19, and 5.24 rad•s21). Significant reductions in isokinetic torque at 0.52 rad from full extension (T30) were observed after high-intensity endurance exercise. Endurance exercise also caused significant reductions in the number of isoinertial squat lifts performed. Plasma lactate values, measured before subjects performed resistance activity, were significantly higher after high intensity endurance exercise (6.16 6 2.28 mmol•L21) when compared with the control condition (0.50 6 0.45 mmol•L21). It was concluded that an acute bout of high-intensity endurance exercise may inhibit performance in a subsequent bout of resistance activity.
To investigate the effects of heavy strength training on the mean power output in a 5-min all-out trial following 185 min of submaximal cycling at 44% of maximal aerobic power output in well-trained cyclists. Twenty well-trained cyclists were assigned to either usual endurance training combined with heavy strength training [E+S; n=11 (♂=11)] or to usual endurance training only [E; n=9 (♂=7, ♀=2)]. The strength training performed by E+S consisted of four lower body exercises [3 × 4-10 repetition maximum (RM)], which were performed twice a week for 12 weeks. E+S increased 1 RM in half-squat (P≤0.001), while no change occurred in E. E+S led to greater reductions than E in oxygen consumption, heart rate, blood lactate concentration, and rate of perceived exertion (P<0.05) during the last hour of the prolonged cycling. Further, E+S increased the mean power output during the 5-min all-out trial (from 371 ± 9 to 400 ± 13 W, P<0.05), while no change occurred in E. In conclusion, adding strength training to usual endurance training improves leg strength and 5-min all-out performance following 185 min of cycling in well-trained cyclists.
The objective of this study was to compare the effect of different strength training protocols added to endurance training on running economy (RE). Sixteen well-trained runners (27.4 +/- 4.4 years; 62.7 +/- 4.3 kg; 166.1 +/- 5.0 cm), were randomized into two groups: explosive strength training (EST) (n = 9) and heavy weight strength training (HWT) (n = 7) group. They performed the following tests before and after 4 weeks of training: 1) incremental treadmill test to exhaustion to determine of peak oxygen uptake and the velocity corresponding to 3.5 mM of blood lactate concentration; 2) submaximal constant-intensity test to determine RE; 3) maximal countermovement jump test and; 4) one repetition maximal strength test in leg press. After the training period, there was an improvement in RE only in the HWT group (HWT = 47.3 +/- 6.8 vs. 44.3 +/- 4.9 ml . kg (-1) . min (-1); EST = 46.4 +/- 4.1 vs. 45.5 +/- 4.1 ml . kg (-1) . min (-1)). In conclusion, a short period of traditional strength training can improve RE in well-trained runners, but this improvement can be dependent on the strength training characteristics. When comparing to explosive training performed in the same equipment, heavy weight training seems to be more efficient for the improvement of RE.
Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The training period resulted in increases in the concentrations of serum testosterone from 19.8 +/- 5.3 to 25.1 +/- 5.2 nmol/l (P less than 0.05), luteinizing hormone (LH) from 8.6 +/- 0.8 to 9.1 +/- 0.8 U/l (P less than 0.05), follicle-stimulating hormone (FSH) from 4.2 +/- 2.0 to 5.3 +/- 2.3 U/l (P less than 0.01), and testosterone-to-serum sex hormone-binding globulin (SHBG) ratio (P less than 0.05). The annual mean value of the second follow-up year for the serum testosterone-to-SHBG ratio correlated significantly (r = 0.84, P less than 0.01) with the individual changes during the 2nd yr in the averaged concentric power. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.
The phrenic nerves were stimulated bilaterally in human subjects with supermaximal shocks and the transdiaphragmatic pressure (Pdi) twitches recorded at end-expiratory lung volume with glottis closed. Stimulus maximality was monitored by the evoked muscle potentials. The highly reproducible twitch amplitudes elicited from the relaxed diaphragm were greater with bound (48 +/- 13 cm H2O) than unbound (34.6 +/- 10 cm H2O) abdomen in sitting position. With bound abdomen, the twitch amplitudes were similar in sitting and supine positions. When the same stimuli were applied during voluntary contractions the superimposed twitch amplitude declined almost linearly with the voluntary Pdi exerted, reflecting a progressively increasing activation by the CNS. From this relationship both the maximal Pdi (Pdimax) and the relative degree of diaphragm activation (% Pdimax) can be estimated for any type of breathing effort. Generally no twitch could be detected during maximal efforts (Pdimax: 218 +/- 34 cm H2O) indicating that all stimulated motor units were already fully activated. The Pditwitch/Pdimax ratio of 0.21 +/- 0.04 was similar to the twitch/tetanus ratios of isolated mammalian muscle, suggesting that bilateral stimulation can activate all phrenic motor neurons.
The purpose of this study was to determine how individuals adapt to a combination of strength and endurance training as compared to the adaptations produced by either strength or endurance training separately. There were three exercise groups: a strength group (S) that exercised 30--40 min . day-1, 5 days . week-1, and endurance group (E) that exercised 40 min . day-1, 6 days . week-1; and an S and E group that performed the same daily exercise regimens as the S and E groups. After 10 weeks of training, VO2max increased approx. 25% when measured during bicycle exercise and 20% when measured during treadmill exercise in both E, and S and E groups. No increase in VO2max was observed in the S group. There was a consistent rate of development of leg-strength by the S group throughout the training, whereas the E group did not show any appreciable gains in strength. The rate of strength improvement by the S and E group was similar to the S group for the first 7 weeks of training, but subsequently leveled off and declined during the 9th and 10th weeks. These findings demonstrate that simultaneously training for S and E will result in a reduced capacity to develop strength, but will not affect the magnitude of increase in VO2max.
In the exercising human, maximal oxygen uptake (VO2max) is limited by the ability of the cardiorespiratory system to deliver oxygen to the exercising muscles. This is shown by three major lines of evidence: 1) when oxygen delivery is altered (by blood doping, hypoxia, or beta-blockade), VO2max changes accordingly; 2) the increase in VO2max with training results primarily from an increase in maximal cardiac output (not an increase in the a-v O2 difference); and 3) when a small muscle mass is overperfused during exercise, it has an extremely high capacity for consuming oxygen. Thus, O2 delivery, not skeletal muscle O2 extraction, is viewed as the primary limiting factor for VO2max in exercising humans. Metabolic adaptations in skeletal muscle are, however, critical for improving submaximal endurance performance. Endurance training causes an increase in mitochondrial enzyme activities, which improves performance by enhancing fat oxidation and decreasing lactic acid accumulation at a given VO2. VO2max is an important variable that sets the upper limit for endurance performance (an athlete cannot operate above 100% VO2max, for extended periods). Running economy and fractional utilization of VO2max also affect endurance performance. The speed at lactate threshold (LT) integrates all three of these variables and is the best physiological predictor of distance running performance.
It has been suggested that endurance training influences the running economy (CR) and the oxygen uptake (.VO(2)) kinetics in heavy exercise by accelerating the primary phase and attenuating the .VO(2) slow component. However, the effects of heavy weight training (HWT) in combination with endurance training remain unclear. The purpose of this study was to examine the influence of a concurrent HWT+endurance training on CR and the .VO(2) kinetics in endurance athletes.
Fifteen triathletes were assigned to endurance+strength (ES) or endurance-only (E) training for 14 wk. The training program was similar, except ES performed two HWT sessions a week. Before and after the training period, the subjects performed 1) an incremental field running test for determination of .VO(2max) and the velocity associated (V(.VO2max)), the second ventilatory threshold (VT(2)); 2) a 3000-m run at constant velocity, calculated to require 25% of the difference between .VO(2max) and VT(2), to determine CR and the characteristics of the VO(2) kinetics; 3) maximal hopping tests to determine maximal mechanical power and lower-limb stiffness; 4) maximal concentric lower-limb strength measurements.
After the training period, maximal strength were increased (P < 0.01) in ES but remained unchanged in E. Hopping power decreased in E (P < 0.05). After training, economy (P < 0.05) and hopping power (P < 0.001) were greater in ES than in E. .VO(2max), leg hopping stiffness and the .VO(2) kinetics were not significantly affected by training either in ES or E.
Additional HWT led to improved maximal strength and running economy with no significant effects on the .VO(2) kinetics pattern in heavy exercise.
The aim of this experiment was to examine the effects of maximal strength training with emphasis on neural adaptations on strength- and endurance-performance for endurance trained athletes. Nineteen male cross-country skiers about 19.7 +/- 4.0 years of age and a maximal oxygen uptake (VO(2 max)) of 69.4 +/- 2.2 mL x kg(-1) x min(-1) were randomly assigned to a training group (n = 9) or a control group (n = 10). Strength training was performed, three times a week for 8 weeks, using a cable pulley simulating the movements in double poling in cross-country skiing, and consisted of three sets of six repetitions at a workload of 85% of one repetition maximum emphasizing maximal mobilization of force in the concentric movement. One repetition maximum improved significantly from 40.3 +/- 4.5 to 44.3 +/- 4.9 kg. Time to peak force (TPF) was reduced by 50 and 60% on two different submaximal workloads. Endurance performance measured as time to exhaustion (TTE) on a double poling ski ergometer at maximum aerobic velocity, improved from 6.49 to 10.18 min; 20.5% over the control group. Work economy changed significantly from 1.02 +/- 0.14 to 0.74 +/- 0.10 mL x kg(-0.67) x min(-1). Maximal strength training with emphasis on neural adaptations improves strength, particularly rate of force development, and improves aerobic endurance performance by improved work economy.
Previous research has reported that plyometric training improves running economy (RE) and ultimately distance-running performance, although the exact mechanism by which this occurs remains unclear. This study examined whether changes in running performance resulting from plyometric training were related to alterations in lower leg musculotendinous stiffness (MTS). Seventeen male runners were pre- and post-tested for lower leg MTS, maximum isometric force, rate of force development, 5-bound distance test (5BT), counter movement jump (CMJ) height, RE, VO(2max), lactate threshold (Th(la)), and 3-km time. Subjects were randomly split into an experimental (E) group which completed 6 weeks of plyometric training in conjunction with their normal running training, and a control (C) group which trained as normal. Following the training period, the E group significantly improved 3-km performance (2.7%) and RE at each of the tested velocities, while no changes in VO(2max) or Th(la) were recorded. CMJ height, 5BT, and MTS also increased significantly. No significant changes were observed in any measures for the C group. The results clearly demonstrated that a 6-week plyometric programme led to improvements in 3-km running performance. It is postulated that the increase in MTS resulted in improved RE. We speculate that the improved RE led to changes in 3-km running performance, as there were no corresponding alterations in VO(2max) or Th(la).
The purpose of this experiment was to examine the effects of concurrent endurance and explosive strength training on electromyography (EMG) and force production of leg extensors, sport-specific rapid force production, aerobic capacity, and work economy in cross-country skiers. Nineteen male cross-country skiers were assigned to an experimental group (E, n = 8) or a control group (C, n = 11). The E group trained for 8 weeks with the same total training volume as C, but 27% of endurance training in E was replaced by explosive strength training. The skiers were measured at pre- and post training for concentric and isometric force-time parameters of leg extensors and EMG activity from the vastus lateralis (VL) and medialis (VM) muscles. Sport-specific rapid force production was measured by performing a 30-m double poling test with the maximal velocity (V(30DP)) and sport-specific endurance economy by constant velocity 2-km double poling test (CVDP) and performance (V(2K)) by 2-km maximal double poling test with roller skis on an indoor track. Maximal oxygen uptake (Vo(2)max) was determined during the maximal treadmill walking test with the poles. The early absolute forces (0-100 ms) in the force-time curve in isometric action increased in E by 18 +/- 22% (p < 0.05), with concomitant increases in the average integrated EMG (IEMG) (0-100 ms) of VL by 21 +/- 21% (p < 0.05). These individual changes in the average IEMG of VL correlated with the changes in early force (r = 0.86, p < 0.01) in E. V(30DP) increased in E (1.4 +/- 1.6%) (p < 0.05) but not in C. The V(2K) increased in C by 2.9 +/- 2.8% (p < 0.01) but not significantly in E (5.5 +/- 5.8%, p < 0.1). However, the steady-state oxygen consumption in CVDP decreased in E by 7 +/- 6% (p < 0.05). No significant changes occurred in Vo(2)max either in E or in C. The present concurrent explosive strength and endurance training in endurance athletes produced improvements in explosive force associated with increased rapid activation of trained leg muscles. The training also led to more economical sport-specific performance. The improvements in neuromuscular characteristics and economy were obtained without a decrease in maximal aerobic capacity, although endurance training was reduced by about 20%.
The present study investigated the effect of maximal strength training on running economy (RE) at 70% of maximal oxygen consumption (V[spacing dot above]O2max) and time to exhaustion at maximal aerobic speed (MAS). Responses in one repetition maximum (1RM) and rate of force development (RFD) in half-squats, maximal oxygen consumption, RE, and time to exhaustion at MAS were examined.
Seventeen well-trained (nine male and eight female) runners were randomly assigned into either an intervention or a control group. The intervention group (four males and four females) performed half-squats, four sets of four repetitions maximum, three times per week for 8 wk, as a supplement to their normal endurance training. The control group continued their normal endurance training during the same period.
The intervention manifested significant improvements in 1RM (33.2%), RFD (26.0%), RE (5.0%), and time to exhaustion at MAS (21.3%). No changes were found in V[spacing dot above]O2max or body weight. The control group exhibited no changes from pre to post values in any of the parameters.
Maximal strength training for 8 wk improved RE and increased time to exhaustion at MAS among well-trained, long-distance runners, without change in maximal oxygen uptake or body weight.