Table 1 - uploaded by Abdelhak Boudhar
Content may be subject to copyright.
Source publication
Resisted sled sprint (RSS) training is an effective modality for the improvement of linear sprint speed. Previous methods of RSS load prescription e.g. an absolute load or as a percentage of body mass (%BM), do not account for inter-individual differences in strength, power or speed characteristics, although the 'maximum resisted sled load' (MRSL)...
Context in source publication
Context 1
... Composition and Anthropometry. The test battery and testing variables performed in this study and their accompanying abbreviations used throughout the text are found in Table 1. Participant height (Ht) and BM were measured using, respectively, a stadiometer (Leicester Height Measurer, Birmingham, United Kingdom) to the nearest 0.01 m and mechanical column scales (SECA 756; SECA UK, Birmingham, United Kingdom) to nearest 0.1 kg. ...
Similar publications
We present an X-band high-power pulse compression system for a klystron-based compact linear collider. In this system design, one rf power unit comprises two klystrons, a correction cavity chain, and two SLAC Energy Doubler (SLED)-type X-band pulse compressors (SLEDX). An rf pulse passes the correction cavity chain, by which the pulse shape is modi...
The use of anthropomorphic test devices (ATDs) for calculating injury risk of occupants in spaceflight scenarios is crucial for ensuring the safety of crewmembers. Finite element (FE) modeling of ATDs reduces cost and time in the design process. The objective of this study was to validate a Hybrid III ATD FE model using a multi-direction test matri...
The application of remote video technologies can provide alternative views of in situ behavior and distribution of aquatic organisms that might be missed with traditional net‐based techniques. We describe a remote benthic video camera system designed to quantify epibenthic density of the macroinvertebrate Mysis diluviana. We deployed the camera mul...
Rear-end impacts are the most common crash scenario in the United States. Although automated vehicle (AV) technologies, such as frontal crash warning (FCW) and automatic emergency braking (AEB), are mitigating and preventing rear-end impacts, the technology is only gradually being introduced and currently has only limited effectiveness. Accordingly...
Citations
... Partial correlations controlling for mass were also calculated between these performance variables, as body size has been shown to confound parameters of physical performance tasks. Correlations were set as <0.1 = trivial, 0.1 to 0.3 = small, 0.3 to 0.5 = moderate, 0.5 to 0.7 = large, 0.7 to 0.9 = very large, >0.9 = nearly perfect, and 1.0 = perfect Petrakos et al. 2017). Statistical significance was set at p ≤ 0.05. ...
The purpose of this study was to evaluate the relationship between the dynamic strength index (DSI) and the lower-body Force-velocity (F-v) profile. Eighty-six (n = 58 females) resistance-trained individuals were recruited to perform both the DSI and F-v profile testing protocols to evaluate this relationship, as well as relationships between the components that comprise each test. Spearman correlations were calculated between DSI, F-v profile slope, countermovement jump (CMJ) peak force (PF), isometric mid-thigh pull (IMTP) PF, and CMJ peak velocity (PV) across a series of loading conditions from an unloaded CMJ to an additional 100% bodyweight (BW) CMJ condition. No significant correlations (rs = 0.01; p > 0.05) were found between the DSI value and the F-v profile slope. Significant correlations were found between the DSI and CMJ/IMTP PF (rs range = -0.63 to 0.22; p < 0.05) and between CMJ/IMTP PF and measures of CMJ PV (rs range = 0.45 to 0.73; p < 0.05) across the loading conditions. Results suggest that the DSI is not correlated to the F-v profile slope. Two different means of evaluating muscular force in athletes are not correlated; we suggest that athletes require specific evaluations for specific performance characteristics when assessing muscular force.
... However, the use of %BM to prescribe a RSS sled load is not sensitive to individual athletic characteristics, and even a standardized %BM can produce large interindividual variability in % V dec (8) and relative intensity of the stimulus (31). To date, investigation of PAPE via RSS have generally prescribed the RSS load using %BM (i.e., 10, 20, and 30%BM (34); 25-30%BM (39,44); 45-50%BM (24,36); 75 and 150%BM (43)) with only 2 studies to date having employed %V dec as the method RSS prescription (9,40). ...
... Because the general principles of CA prescription for PAPE require maximal, or near maximal, muscle contraction to induce a potentiating effect (19,33,41), careful consideration of the RSS stimulus and the application of H-RSS or VH-RSS loads may be required. However, the use of %BM to prescribe a RSS load is not sensitive to individual athletic characteristics and its effect on intensity is influenced by the running surface such that even a standardized %BM can produce large interindividual variability in %V dec (8) and relative intensity of the stimulus (31). In other words, it is difficult to translate or interpret studies that have used %BM unless %V dec is also measured because the running surface, sled characteristics, and accompanying coefficient of friction will largely determine the relationship between %BM and %V dec . ...
The effect of resisted sled sprinting (RSS) on postactivation performance enhancement (PAPE) was investigated in team field sport athletes (n 5 28; m and female, 15 and 13; age, 22.1 6 2.5 years; height, 1.77 6 0.11 m; body mass [BM], 75.1 6 16.4 kg). After a standardized warm-up, unresisted sprint (URS) performance was measured over 10-and 20-m (PRE) followed by a conditioning activity (CA) consisting of 3 3 20 m RSS. Unresisted sprint performance was then measured again at 30 seconds and 4, 8, 12, 16, 20, and 24 minutes after CA. The effect of heavy (H-RSS) or very heavy (VH-RSS) sled loads were compared during 2 separate visits using a randomized crossover design. Heavy-resisted sled sprinting and VH-RSS loads corresponded to a velocity decrement (V dec) of 17.3 6 3.6% V dec (20.0 6 2.3%BM) and 52.9 6 3.8%V dec (64.3 6 7.0%BM), respectively. Unresisted sprint performance after CA was slower than PRE over 10-and 20-m (both p , 0.001 for time). The decline in URS performance over 20-m was greater in VH-RSS (time 3 sled load interaction, p 5 0.033). However, after extraction of the fastest sprint times after CA, the fastest sprint time for 10-m improved after H-RSS by 0.026 (0.001, 0.050) seconds (p 5 0.040; d 5 0.21) but not after VH-RSS (p 5 0.054; d 5 0.14). The fastest sprint times for 20-m were similar to PRE after H-RSS and VH-RSS. No sex-specific differences were observed. Given the high intersubject variability in the magnitude of improvement, and for the time point at which the fastest sprint occurred, there remains questionable practical value to an RSS-based CA as a means to induce a PAPE for URS performance.
... Assessment of MRSL is analogous to the assessment of 1 repetition maximum (1RM) in traditional resistance exercise training and was performed to establish each individual's performance ability for RSS over 20 m in each subject. In brief, subjects complete a series of RSS over 20 m at progressively higher sled loads based on %BM (18,24). The sled load corresponding to MRSL is identified as the heaviest sled load that allows a subject to continue to accelerate over the final 5 m of a 20 m sprint (18), determined using the location of infrared single-beam speed gates (Fusion Sport, QLD, Australia) at 0, 10, 15, and 20 m as previously described (18,24). ...
... In brief, subjects complete a series of RSS over 20 m at progressively higher sled loads based on %BM (18,24). The sled load corresponding to MRSL is identified as the heaviest sled load that allows a subject to continue to accelerate over the final 5 m of a 20 m sprint (18), determined using the location of infrared single-beam speed gates (Fusion Sport, QLD, Australia) at 0, 10, 15, and 20 m as previously described (18,24). Assessment of MRSL has been demonstrated to have excellent reliability (ICC 5 0.95) (24). ...
... The sled load corresponding to MRSL is identified as the heaviest sled load that allows a subject to continue to accelerate over the final 5 m of a 20 m sprint (18), determined using the location of infrared single-beam speed gates (Fusion Sport, QLD, Australia) at 0, 10, 15, and 20 m as previously described (18,24). Assessment of MRSL has been demonstrated to have excellent reliability (ICC 5 0.95) (24). Sled loads for L-RSS and H-RSS in subsequent testing sessions were individualized and prescribed as 30 and 80%, respectively, of a subject's MRSL (Table 1). ...
The acute physiological and perceptual responses to a single session of resisted sled sprint (RSS) training are largely unexplored, nor have differences, if any, between male and female athletes been compared. Team field sport athletes (n 5 27; male/female, 15/12; 21.1 6 2.7 years) were assessed for Maximal Resisted Sled Load (MRSL) from which light (L-RSS, 30%MRSL) and heavy (H-RSS, 80%MRSL) sled loads were prescribed. On separate occasions in random order, 2 training sessions of 12 3 20 m RSS repetitions at either L-or H-RSS were performed, and assessments of physiological and perceptual responses were performed before (PRE), during, after (POST) and 24 hours after (+24 hours POST) each session. Compared to unresisted sprints, velocity decrements of 7.5 6 2.2 and 22.7 6 8.1% were produced by L-RSS and H-RSS, respectively. Heart rate, blood lactate, and ratings of perceived exertion were higher in H-RSS compared to L-RSS. Decrements in 20 m sprint and countermovement jump performance observed at POST had returned to PRE values at +24 hours POST. Except for a higher heart rate (;7-12 b·min 21) in females during the respective sessions, responses to Land H-RSS were generally similar between males and females. A single session of heavy RSS training is more demanding than light RSS training when matched for sprint number and distance, but measures of lower limb power and sprint performance return to pre-training levels within 24 hours regardless of sled load. Males and females respond similarly to a single session of RSS training when individualized, relative intensity sled loads are prescribed.
... 5,6 Consequently, more qualitative methods of sled load prescription have been suggested to individualize training and minimize the between-athlete variation, such as assessing the velocity decrement (V dec ) caused from sled loading from one's maximal speed. 6,7 Force-velocity profiling (FV) during unresisted sprinting can offer the coach valuable insights into the individual characteristics of each athlete and how to individualize load specific to their force or velocity dominancy. Specific to sled towing, sprint phase adaptation is related to the resistive stimulus, with heavier loads eliciting greatest gains in early acceleration, and lighter loads or unresisted sprinting benefiting the latter phases and maximal velocity. ...
... 4,20 More recent research has used novel methods of load prescription focusing on the decrement in velocity that each load causes from maximal unresisted sprint speed. [5][6][7] Other research has suggested assessing one's force-velocity (f-v) profile during the unresisted sprint trial to determine if the athlete is force or velocity dominant. 21 This method has been suggested as a more qualitative approach to optimize training and assess the effectiveness of ST interventions. ...
The purpose of this study was to assess current perceptions of strength and conditioning coaches’ use of sled towing (ST) as part of their training programs. One-hundred and twenty-five coaches responded to a survey of their ST practices. Themes investigated included the primary purpose and usefulness of using ST, the loads used in short and long distances, rest times between sprints, total volume of ST sprints per session, frequency of ST activity each month, and whether coaches engaged in force-velocity profiling in ST sprints. Eighty percent of coaches either agreed or strongly agreed that ST is a useful intervention tool for improving athletic performance. Speed strength was the physiological adaptation most sought after to improve ( n = 75) followed by power ( n = 72). Bodyweight (BW) loads of 20% were the most common across all distances. The two most common rest times given between each ST repetition were one to two minutes ( n = 37) and two to three minutes ( n = 37). The most common volume responses for individual training sessions were five to eight sprints ( n = 52) and three to five times per month, respectively. These data suggest strength and conditioning coaches view ST as an integral part of programming, primarily use loads of 20% BW for both short and long sprints and seek to optimize a number of different physiological adaptations. The majority of coaches have a favorable view of ST (88%); however, current training parameters used by strength and conditioning coaches may be inadequate to achieve their desired adaptations.
... A previous limitation of sled-pull training is the use of loading based solely on a set percentage of body mass (%BM) for all individuals because friction, strength, training history, and maturation are all likely to influence the relative ability to tolerate external loads (3,29). An alternative method for loading a sled involves providing subjects with a load that causes a given reduction in maximal velocity when compared with unresisted sprinting (Vdec) (7,27). Using this method, the highly linear relationships between force-velocity and loadvelocity during sled pulling has allowed researchers to determine the optimal sled load (Lopt) to maximize power production (3,7). ...
Cahill, MJ, Oliver, JL, Cronin, JB, Clark, K, Cross, MR, Lloyd, RS, and Lee, JE. Influence of resisted sled-pull training on the sprint force-velocity profile of male high-school athletes. J Strength Cond Res XX(X): 000-000, 2020-Although resisted sled towing is a commonly used method of sprint-specific training, little uniformity exists around training guidelines for practitioners. The aim of this study was to assess the effectiveness of unresisted and resisted sled-pull training across multiple loads. Fifty-three male high-school athletes were assigned to an unresisted (n 5 12) or 1 of 3 resisted groups: light (n 5 15), moderate (n 5 14), and heavy (n 5 12) corresponding to loads of 44 6 4 %BM, 89 6 8 %BM, and 133 6 12 %BM that caused a 25, 50, and 75% velocity decrement in maximum sprint speed, respectively. All subjects performed 2 sled-pull training sessions twice weekly for 8 weeks. Split times of 5, 10, and 20 m improved across all resisted groups (d 5 0.40-1.04, p , 0.01) but did not improve with unresisted sprinting. However, the magnitude of the gains increased most within the heavy group, with the greatest improvement observed over the first 10 m (d $ 1.04). Changes in preintervention to postintervention force-velocity profiles were specific to the loading prescribed during training. Specifically, F 0 increased most in moderate to heavy groups (d 5 1.08-1.19); Vmax significantly decreased in the heavy group but increased in the unresisted group (d 5 012-0.44); whereas, Pmax increased across all resisted groups (d 5 0.39-1.03). The results of this study suggest that the greatest gains in short distance sprint performance, especially initial acceleration, are achieved using much heavier sled loads than previously studied in young athletes.
... However, further research is required to confirm this hypothesis. In agreement with our findings, Petrakos et al. (27) reported that maximal resisted sled load (MRSL; i.e., the final sled load before an athlete can no longer accelerate between 10 and 15-m and 15 and 20-m) was correlated with unloaded sprint speed (r 5 0.51-0.56). Likewise, Martínez-Valencia et al. (21) observed a significant relationship (r 5 20.71) between unloaded sprint time and MRSL. ...
... These relationships were larger as the loads used during resisted sprints increased (r 5 20.54 to 20.71, p , 0.001). Similarly, Petrakos et al. (27) reported significant correlations between MRSL and vertical jump height (r 5 0.59) and power (r 5 0.56) in female athletes. These authors suggested that athletes with greater general concentric power are likely able to produce greater forces at higher velocities and, hence, obtain greater resisted sprint performance under heavier loading intensities as compared with less powerful athletes (27). ...
... Similarly, Petrakos et al. (27) reported significant correlations between MRSL and vertical jump height (r 5 0.59) and power (r 5 0.56) in female athletes. These authors suggested that athletes with greater general concentric power are likely able to produce greater forces at higher velocities and, hence, obtain greater resisted sprint performance under heavier loading intensities as compared with less powerful athletes (27). In addition, in our study, unloaded and loaded jump height presented significant relationships with VL-50%BM, and jump HL correlated significantly with unresisted and resisted sprint times. ...
Lizana, JA, Bachero-Mena, B, Calvo-Lluch, A, Sánchez-Moreno, M, Pereira, LA, Loturco, I, and Pareja-Blanco, F. Do faster, stronger, and more powerful athletes perform better in resisted sprints? J Strength Cond Res XX(X): 000-000, 2020-This study aimed to analyze the relationships between different strength, power, and speed abilities and resisted sprint performance across a wide range of sled loads (10, 30, and 50% body mass [BM]). Seventy-nine young physically active male sport science students (age: 22.8 ± 3.4 years, BM: 74.2 ± 9.1 kg, and height: 175.4 ± 8.5 cm) performed 2 testing sessions. Session 1 consisted of a 20 m sprint without any additional load and with 10, 30, and 50% BM. Session 2 consisted of countermovement jump and full squat (SQ) tests. The CMJ was performed without any additional load and with loads of 30 and 50% BM, and the SQ was performed with loads corresponding to 30, 50, 70, and 90% BM. Resisted sprint times were moderate to large correlated with unloaded sprint times (r = 0.79 to 0.89), unloaded and loaded jump height (r = -0.62 to -0.71), and SQ performance (r = -0.56 to -0.71). Negative relationships were observed between velocity loss induced by each sled load and jump and SQ performance. The magnitude of these relationships increased with increasing sled loads. In conclusion, differences in speed, strength, and power abilities may explain, at least partially, the individual response of each athlete during sprinting towing a sled, especially with heavier sled loads. Thus, faster, stronger, and more powerful athletes require heavier sled loads (relative to %BM) to experience similar exercise intensities.
... Reliability analysis demonstrated no systematic bias in any of the variables, suggesting the absence of any learning effects, which agrees with previous research in adult populations 49,93,100 . This is the first study to examine the reliability of resisted sled pulling in young athletes. ...
... Optimizing load might be considered the variable of most interest for resisted sled training prescription, and this had low random variation with CVs < 5%. Intra-class correlation coefficients were The high degree of reliability shown in the current study are congruent with previous research examining sled load prescription 49,93 . The lack of systematic bias and stable random variation across trials suggests there were no improvements in reliability across trials, which may be partly due to the familiarization to sled pulling prior to data collection. ...
... High reliability was demonstrated for Vmax, L25, L50 and L75. The high degree of reliability expressed for loading prescription within specific zones and the consistency of the LV profile in this study are underpinned by the reliability found in the slope of the individual load-velocity relationships, which agrees with previous research on resisted sled pulling 49,93 . All CVs were found to be within an acceptable range of <10% for the three outcome variables of interest across all loads indicating acceptable reliability. ...
Speed is an important athletic quality and needs to be developed in young athletes, this may be best achieved using specific forms of sprint training. Resisted sled training is a sprint specific form of training widely used by coaches and practitioners. The two modes of resisted sled training that exist are sled pushing and pulling, with limited research available for pulling and little, if any, available for pushing in any population. The overarching question that guided this thesis was “what are the acute and chronic training responses to sled pushing and pulling in young athletes?”
The aims of the thesis were to: review existing literature related to acute and chronic training responses to resisted sled pushing and pulling; examine the reliability, linearity, and utility of individual load-velocity profiles to prescribe training loads during sled pushing and pulling in young athletes; assess the effectiveness of unresisted and resisted sled pull and sled push training on short distance sprint performance across a wide array of individualised loads; and, provide practical programming guidelines on how to integrate resisted sled training into an athlete’s training.
The main findings of this thesis were: 1) across existing literature little uniformity exists with regard to prescription of load for resisted sled training although heavier loads appeared to provide a stimulus for higher horizontal force application. Loads can be applied across different zones of training such as technical competency, speed-strength, power and strength-speed. 2) Sled pushing and pulling produce a highly linear relationship (r > 0.95) between load and velocity. The slope of the load-velocity relationship was found to be reliable (CV = 3.1%), with the loads that cause a decrement in velocity of 25, 50 and 75% also found to be reliable (CVs = <5%). However, there was large between-participant variation (95%CI) in the load that caused a given Vdec in both sled pushing and pulling. Loads of 14-21, 36-53, 71-107 and 107-160% body mass (%BM) caused a Vdec of 10, 25, 50 and 75% in sled pulling. Loads of 23-42, 45-85 and 69-131% body mass (%BM) caused a Vdec of 25, 50 and 75% in sled pushing. 3) Both forms of resisted sprint training demonstrated a clear trend for greater and more consistent improvements in sprinting force, power and performance over short distances when training with heavier sled loads (as compared to a lighter load or unresisted sprint training).
Several practical applications may be offered from the findings. Due to the linearity and reliability of the load-velocity relationship, coaches are urged to prescribe individualised sled loads based on a target decrement in velocity rather than simply prescribing all athletes the same load as a set percentage of body mass. Both sled pushing and pulling were effective sprint specific modes of training to enhance overall sprint performance, with the latter found to be more sprint specific due to the use of the arms. Heavier loads during both forms of resisted sled training appeared to yield the greatest benefit to young athletes in short distance sprint performance, however a targeted approach to sled loading may influence different phases of the sprint.
... High reliability was demonstrated for Vmax, L 25 , L 50 , and L 75 . The high degree of reliability expressed for loading prescription within specific zones and the consistency of the LV profile in this study are underpinned by the reliability found in the slope of the individual LV relationships, which agrees with previous research on resisted sled pulling (8,25). All CVs were found to be within an acceptable range of ,10% for the 3 outcome variables of interest across all loads indicating acceptable reliability. ...
Cahill, M, Oliver, JL, Cronin, JB, Clark, K, Cross, MR, and Lloyd, RS. Sled-push load-velocity profiling and implications for sprint training prescription in young athletes. J Strength Cond Res XX(X): 000-000, 2019-Resisted sled pushing is a popular method of sprint-specific training; however, little evidence exists to support the prescription of resistive loads in young athletes. The purpose of this study was to determine the reliability and linearity of the force-velocity relationship during sled pushing, as well as the amount of between-athlete variation in the load required to cause a decrement in maximal velocity (Vdec) of 25, 50, and 75%. Ninety (n 5 90) high school, male athletes (age 16.9 6 0.9 years) were recruited for the study. All subjects performed 1 unresisted and 3 sled-push sprints with increasing resistance. Maximal velocity was measured with a radar gun during each sprint and the load-velocity (LV) relationship established for each subject. A subset of 16 subjects examined the reliability of sled pushing on 3 separate occasions. For all individual subjects, the LV relationship was highly linear (r. 0.96). The slope of the LV relationship was found to be reliable (CV AU5 5 3.1%), with the loads that cause a decrement in velocity of 25, 50, and 75% also found to be reliable (CVs 5 ,5%). However, there was large between-subject variation (95% confidence interval) in the load that caused a given Vdec, with loads of 23-42% body mass (%BM) causing a Vdec of 25%, 45-85 %BM causing a Vdec of 50%, and 69-131 %BM causing a Vdec of 75%. The Vdec method can be reliably used to prescribe sled-push loads in young athletes, but practitioners should be aware that the load required to cause a given Vdec is highly individualized.
... Sports 2019, 7, 119 2 of 10 sled sprinting, specifically sled pulling, as a popular and effective method of sprint training [5,6]. As with traditional resistance training, the resistive load used during sled pulling needs to be appropriately prescribed to cause the desired training adaptations. ...
... The majority of previous sled pulling research has been studied in adult populations and has prescribed lighter loads (<30% body mass) with the emphasis on ensuring minimal disruption in sprint mechanics and small acute reductions in speed [7,8]. The reliability of resisted sled sprinting has been studied in adult populations [5]. However, the reliability across multiple loads from light to heavy has not been examined in young athletes. ...
... Reliability analysis demonstrated no systematic bias in any of the variables, suggesting the absence of any learning effects, which is in agreement with previous research in adult populations [5,9,16]. This is the first study to examine the reliability of resisted sled pulling in young athletes. ...
The purpose of this study was to examine the usefulness of individual load-velocity profiles and the between-athlete variation using the decrement in maximal velocity (Vdec) approach to prescribe training loads in resisted sled pulling in young athletes. Seventy high school, team sport, male athletes (age 16.7 ± 0.8 years) were recruited for the study. All participants performed one un-resisted and four resisted sled-pull sprints with incremental resistance of 20% BM. Maximal velocity was measured with a radar gun during each sprint and the load-velocity relationship established for each participant. A subset of 15 participants was used to examine the reliability of sled pulling on three separate occasions. For all individual participants, the load-velocity relationship was highly linear (r > 0.95). The slope of the load-velocity relationship was found to be reliable (coefficient of variation (CV) = 3.1%), with the loads that caused a decrement in velocity of 10, 25, 50, and 75% also found to be reliable (CVs = <5%). However, there was a large between-participant variation (95% confidence intervals (CIs)) in the load that caused a given Vdec, with loads of 14-21% body mass (% BM) causing a Vdec of 10%, 36-53% BM causing a Vdec of 25%, 71-107% BM causing a Vdec of 50%, and 107-160% BM causing a Vdec of 75%. The Vdec method can be reliably used to prescribe sled-pulling loads in young athletes, but practitioners should be aware that the load required to cause a given Vdec is highly individualized.
... While the literature included in the analyses appears complete (permitting submission and processing time), there are several relevant studies strangely absent from the bibliography. For example, uncited works include those pertaining to friction and resistance computation for sleds [5,6], reviews on Fv profiling and optimized loading in sprinting [17], sprinting performance determinants [10,11,14,16,23], theorem of using targeted horizontal resistance [12], resisted sprinting loading selection [19,24,25], and 'acute' measurements of physical and technical outputs using sleds [26][27][28][29]. We support critical and reasoned exclusion of non-relevant citations, but reviews should provide a balanced and exhaustive overview of a topic. ...
