David G Behm - Profile on Academia.edu (original) (raw)

Papers by David G Behm

PLOS ONE

Background The goal of this study was to determine if 10-min of anodal transcranial direct curren... more Background The goal of this study was to determine if 10-min of anodal transcranial direct current stimulation (a-tDCS) to the motor cortex (M1) is capable of modulating quadriceps isometric maximal voluntary contraction (MVC) force or fatigue endurance contralateral or ipsilateral to the stimulation site. Methods In a randomized, cross-over design, 16 (8 females) individuals underwent two sessions of a-tDCS and two sham tDCS (s-tDCS) sessions targeting the left M1 (all participants were right limb dominant), with testing of either the left (ipsilateral) or right (contralateral) quadriceps. Knee extensor (KE) MVC force was recorded prior to and following the a-tDCS and s-tDCS protocols. Additionally, a repetitive MVC fatiguing protocol (12 MVCs with work-rest ratio of 5:10-s) was completed following each tDCS protocol. Results There was a significant interaction effect for stimulation condition x leg tested x time [F(1,60) = 7.156, p = 0.010, ηp2 = 0.11], which revealed a significan...

Sports

More than 70% of people with ankle sprain experience chronic ankle instability. However, some peo... more More than 70% of people with ankle sprain experience chronic ankle instability. However, some people are well adapted to this damage (copers) and do not suffer from chronic ankle instability (CAI). This cross-sectional study involved 34 female athletes, who were classified into three groups (athletes with CAI, copers, and healthy athletes) and tested on a Biodex Balance System. Surface electromyography (EMG) and balance scores were monitored. The coper and healthy group exhibited higher medial gastrocnemius (MG) EMG activity during unstable balance conditions. The rectus abdominus (RA) in the coper group and rectus femoris (RF) in the healthy group showed greater EMG activity compared to CAI during unstable conditions. During stable conditions, the coper group showed greater RA EMG activity compared to CAI, as well as higher tibialis anterior (TA) EMG activity compared to the healthy group. Additionally, balance error scores were higher in the CAI group than those in the healthy gro...

Methodological Issues with Transcranial Direct Current Stimulation for Enhancing Muscle Strength and Endurance: A Narrative Review

Journal of Cognitive Enhancement, 2021

In recent years, there has been a substantial increase in the number of studies investigating the... more In recent years, there has been a substantial increase in the number of studies investigating the effects that transcranial direct current stimulation (tDCS) can have on exercise performance. Currently, there exists substantial conflict in the literature, with many studies reporting that 10–20 min of tDCS can result in augmented performance, while other studies also report no significant changes. Throughout the literature, there is considerable variance in the tDCS protocols being administered. These differences include electrode placement, stimulation intensity, stimulation duration, and participant’s sex. This variance may account for some of the discrepancies in the results of published studies. Therefore, the goal of this narrative review was to explore the differences in tDCS protocols among these studies to help determine which variations seem to be most effective at producing muscle strength and endurance performance increases. It is suggested that a standardized set of protocols would be beneficial in order to make the comparison of the literature more straightforward. Although, as it currently stands, more research in certain areas surrounding various tDCS variables is needed to determine the most optimal setup for increasing exercise performance.

Frontiers in Physiology, 2022

The objective of this study was to compare the activation of the core (trunk) musculature during ... more The objective of this study was to compare the activation of the core (trunk) musculature during quadriceps and hamstrings foam rolling (FR) vs. prone and supine/reverse static planks to determine if FR is a viable means of training the core musculature. Using a randomized allocation, nine recreationally trained, young adults (18–26 years) performed two sets each of quadriceps and hamstrings FR as well as supine/reverse and prone static planks for 30-s each with 1-min rest between sets and 5-min rest between exercises. Electromyographic (EMG) activity of the lower abdominals (LA), external obliques (EO), lumbosacral erector spinae (LSES), upper lumbar erector spinae (ULES) muscle groups were normalized to a maximum voluntary contraction and analyzed. Quadriceps FR exhibited a very large magnitude greater LA activity compared to reverse plank (p = 0.033, d = 4.42) and hamstrings FR (p = 0.020, d = 3.49), respectively. The prone plank demonstrated very large magnitude higher EO EMG ac...

International Journal of Environmental Research and Public Health, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Sports Medicine, 2021

Background: Unilateral fatigue and static stretching (SS) can impair performance and increase ran... more Background: Unilateral fatigue and static stretching (SS) can impair performance and increase range of motion of a non-exercised or non-stretched muscle respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective: The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature for future research. Methods: A systematic literature search following the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The Physiotherapy Evidence Database (PEDro) scale was used to assess study risk of bias and methodological quality. Results: Unilateral stretching protocols, from six studies, involved 6.3±2 repetitions of 36.3±7.4 seconds with 19.3±5.7 seconds recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-0.35: 0.01 to-1.8) and contralateral, non-stretched, muscles (-0.22: 0.08 to-1.1). Control measures exhibited trivial deficits. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others. Conclusion: The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude decrements in force output. However, the frequency of these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global effects of prolonged SS.

European Journal of Applied Physiology, 2021

Background: Static stretching (SS) can impair performance and increase range of motion of a nonex... more Background: Static stretching (SS) can impair performance and increase range of motion of a nonexercised or non-stretched muscle respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective: The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature. Methods: A systematic literature search following Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The Physiotherapy Evidence Database scale was used to assess study risk of bias and methodological quality. Results: Unilateral stretching protocols from six studies involved 6.3±2 repetitions of 36.3±7.4 seconds with 19.3±5.7 seconds recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-6.7±7.1%, d=-0.35: 0.01 to-1.8) and contralateral, non-stretched, muscles (-4.0±4.9%, d=-0.22: 0.08 to-1.1). Control measures exhibited trivial deficits. Conclusion: The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude force deficits. However, the frequency of studies with these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global (non-local) effects of prolonged SS. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others.

Applied Physiology, Nutrition, and Metabolism, 2019

Cross-education has been extensively investigated with adults. Adult studies report asymmetrical ... more Cross-education has been extensively investigated with adults. Adult studies report asymmetrical cross-education adaptations predominately after dominant limb training. The objective of the study was to examine unilateral leg press (LP) training of the dominant or nondominant leg on contralateral and ipsilateral strength and balance measures. Forty-two youth (10–13 years) were placed (random allocation) into a dominant (n = 15) or nondominant (n = 14) leg press training group or nontraining control (n = 13). Experimental groups trained 3 times per week for 8 weeks and were tested pre-/post-training for ipsilateral and contralateral 1-repetition maximum (RM) horizontal LP, maximum voluntary isometric contraction (MVIC) of knee extensors (KE) and flexors (KF), countermovement jump (CMJ), triple hop test (THT), MVIC strength of elbow flexors (EF) and handgrip, as well as the stork and Y balance tests. Both dominant and nondominant LP training significantly (p < 0.05) increased both ...

International Journal of Environmental Research and Public Health

Foam rolling (FR) is a new and popular technique for increasing range of motion. While there are ... more Foam rolling (FR) is a new and popular technique for increasing range of motion. While there are a few studies that demonstrate increased performance measures after an acute bout of FR, the overall evidence indicates trivial performance benefits. As there have been no meta-analyses on the effects of chronic FR on performance, the objective of this systematic meta-analytical review was to quantify the effects of FR training on performance. We searched PubMed, Scopus, the Cochrane library, and Web of Science for FR training studies with a duration greater than two weeks, and found eight relevant studies. We used a random effect meta-analysis that employed a mixed-effect model to identify subgroup analyses. GRADE analysis was used to gauge the quality of the evidence obtained from this meta-analysis. Egger’s regression intercept test (intercept 1.79; p = 0.62) and an average PEDro score of 6.25 (±0.89) indicated no or low risk of reporting bias, respectively. GRADE analysis indicated t...

Sports Medicine

Background Although it is known that resistance training can be as effective as stretch training ... more Background Although it is known that resistance training can be as effective as stretch training to increase joint range of motion, to date no comprehensive meta-analysis has investigated the effects of resistance training on range of motion with all its potential affecting variables. Objective The objective of this systematic review with meta-analysis was to evaluate the effect of chronic resistance training on range of motion compared either to a control condition or stretch training or to a combination of resistance training and stretch training to stretch training, while assessing moderating variables. Design For the main analysis, a random-effect meta-analysis was used and for the subgroup analysis a mixed-effect model was implemented. Whilst subgroup analyses included sex and participants’ activity levels, meta-regression included age, frequency, and duration of resistance training. Data Sources Following the systematic search in four databases (PubMed, Scopus, SPORTDiscus, an...

European Journal of Applied Physiology, 2022

Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the ran... more Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the range of motion (ROM) of a joint. However, possible differences in the magnitude of change on ROM between these two interventions on the immediate and prolonged effects (e.g., 10 min after the intervention) are not yet well understood. Thus, the purpose of this review was to compare the immediate and prolonged effects of a single bout of foam rolling with a single bout of stretching on ROM in healthy participants. Methods In total, 20 studies with overall 38 effect sizes were found to be eligible for a meta-analysis. For the main analysis, subgroup analysis, we applied a random-effect meta-analysis, mixed-effect model, respectively. The subgroup analyses included age groups, sex, and activity levels of the participants, as well as the tested muscles, the duration of the application, and the study design. Results Meta-analyses revealed no significant differences between a single stretching a...

European Journal of Applied Physiology, 2022

Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the ran... more Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the range of motion (ROM) of a joint. However, possible differences in the magnitude of change on ROM between these two interventions on the immediate and prolonged effects (e.g., 10 min after the intervention) are not yet well understood. Thus, the purpose of this review was to compare the immediate and prolonged effects of a single bout of foam rolling with a single bout of stretching on ROM in healthy participants. Methods In total, 20 studies with overall 38 effect sizes were found to be eligible for a meta-analysis. For the main analysis, subgroup analysis, we applied a random-effect meta-analysis, mixed-effect model, respectively. The subgroup analyses included age groups, sex, and activity levels of the participants, as well as the tested muscles, the duration of the application, and the study design. Results Meta-analyses revealed no significant differences between a single stretching a...

Journal of Sports Science and Medicine, Nov 24, 2015

JPHR: Journal of Performance Health Research, 2019

Background: Prolonged static stretching (SS) has been shown to impair subsequent performance of a... more Background: Prolonged static stretching (SS) has been shown to impair subsequent performance of a stretched muscle. There is evidence that unilateral SS can have crossover or global effects on range of motion (ROM), but there is scant information regarding whether prolonged SS also impairs the performance of contralateral muscle groups. Purpose: The objective of this study is to investigate the effects of self-administered unilateral SS with a TheraBand ® stretch strap on contralateral hip flexion ROM and knee extension isometric maximum voluntary contraction (MVC) force and muscle activation. Study Design: This study used an experimental repeated-measures intervention design. Methods: In total, 14 male participants performed self-administered SS of the dominant quadriceps and hamstrings (eight repetitions of 30 s each) with a TheraBand stretch strap. The aim was to observe pre-to post-SS-induced changes in hip flexion (hamstrings) ROM, knee extension (quadriceps) isometric force, and muscle activation (as recorded with electromyography [EMG]) in both dominant (experimental limb) and nondominant lower limbs (control lower limb). Results: A significant tested leg  time interaction [F (1,13) = 6.58; P = 0.04; eta 2 = 0.210) demonstrated that the ROM increases in both the stretched and contralateral nonstretched legs by 6.7% (d = 0.53) and 4.3% (d = 0.38), respectively. There were no significant interactions for MVC force or muscle activation for either leg. Conclusion: The lack of crossover MVC changes suggests that the mechanism for contralateral increases in ROM may be stretch tolerance. Clinical Relevance: Individuals who are injured or are undergoing rehabilitation should continue to stretch the noninjured limb to maintain or improve flexibility of the injured limb.

Journal of Strength and Conditioning Research, 2016

Balance training may have a preconditioning effect on subsequent power training with youth. There... more Balance training may have a preconditioning effect on subsequent power training with youth. There are no studies examining whether the sequencing of balance and plyometric training has additional training benefits. The objective was to examine the effect of sequencing balance and plyometric training on the performance of 12-13 years old athletes. Twenty-four young elite soccer players trained twice per week for eight weeks either with an initial four weeks of balance training followed by four weeks of plyometric training (BPT) or four weeks of plyometric training proceeded by four weeks of balance training (PBT). Testing was conducted pre-and post-training and included medicine ball throw, horizontal and vertical jumps, reactive strength, and leg stiffness, agility, 10, 20, 30-m sprints, Standing Stork balance test and Y-Balance Test. Results indicated that BPT provided significantly greater improvements with reactive strength index, absolute and relative leg stiffness, triple hop test (THT) and a trend for the Y balance test (p=0.054) compared to PBT. While all other measures had similar changes for both groups, the average relative improvement for the BPT was 22.4% (d= 1.5) versus 15.0% (d= 1.1) for the PBT. BPT effect sizes were greater with 8 of 13 measures. In conclusion, while either sequence of BPT or PBT improved jumping, hopping, sprint acceleration, and Standing Stork and Y balance; BPT initiated greater training improvements in reactive strength index, absolute and relative leg stiffness, THT and the Y balance test. BPT may provide either similar or superior performance enhancements compared to PBT.

European journal of applied physiology, 2015

Non-local muscle fatigue (NLMF) is characterized by muscle performance impairments in a contralat... more Non-local muscle fatigue (NLMF) is characterized by muscle performance impairments in a contralateral or remote non-exercised muscle(s) following a fatiguing protocol of a different muscle group(s). This topic is of interest as it affords insights into physiological determinants of muscle fatigue and may provide practical applications concerning the order of exercises in training and rehabilitation programs. A literature review was conducted using Web of Science, PubMed, and Google Scholar databases to evaluate the NLMF effects and possible underlying mechanisms. Overall, 35 studies with 58 outcome measures that met the inclusion criteria were identified. The literature is conflicting with approximately half of the studies reporting NLMF effects (32 of 58 measurements). However, on closer examination 76% of outcome measures of the lower limbs reported NLMF effects (23 of 30 measurements) compared to only 32% in the upper body (9 of 28 measurements). Thus, it appears that NLMF effect...

International journal of sports physical therapy, 2015

The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically... more The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically reported to accentuate the subsequent concentric jump performance. Some researchers have rationalized that adding elastic resistance (ER) to explosive type activities (e.g. countermovement jumps and drop jumps) would increase excitatory stretch reflex activity and mechanical recoil characteristics of the musculotendinous tissues. The purpose of this meta-analysis was to examine the available literature on jumping movements augmented with ER and to provide a quantitative summary on the effectiveness of this technique for enhancing acute eccentric and concentric jumping performance. In a random-effects model, the Hedges`s g effect size (ES) was used to calculate the biased corrected standardized mean difference between the augmented and similar non-augmented jumps. The results demonstrated that augmented jumps provided a greater eccentric loading compared to free jumps (Hedges`s g ES = 0....

European Journal of Applied Physiology, 2015

Haddad JSCR 2013 Static Stretching Can Impair Explosive Performance For At Least 24 Hours

PLOS ONE, 2015

Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for y... more Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration) curve. Two groups of eight undergraduate students (n = 16) took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD) drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV)). Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third asessement. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sentitive enough to predict crash risk for young drivers, even when intoxicated.

PLOS ONE

Background The goal of this study was to determine if 10-min of anodal transcranial direct curren... more Background The goal of this study was to determine if 10-min of anodal transcranial direct current stimulation (a-tDCS) to the motor cortex (M1) is capable of modulating quadriceps isometric maximal voluntary contraction (MVC) force or fatigue endurance contralateral or ipsilateral to the stimulation site. Methods In a randomized, cross-over design, 16 (8 females) individuals underwent two sessions of a-tDCS and two sham tDCS (s-tDCS) sessions targeting the left M1 (all participants were right limb dominant), with testing of either the left (ipsilateral) or right (contralateral) quadriceps. Knee extensor (KE) MVC force was recorded prior to and following the a-tDCS and s-tDCS protocols. Additionally, a repetitive MVC fatiguing protocol (12 MVCs with work-rest ratio of 5:10-s) was completed following each tDCS protocol. Results There was a significant interaction effect for stimulation condition x leg tested x time [F(1,60) = 7.156, p = 0.010, ηp2 = 0.11], which revealed a significan...

Sports

More than 70% of people with ankle sprain experience chronic ankle instability. However, some peo... more More than 70% of people with ankle sprain experience chronic ankle instability. However, some people are well adapted to this damage (copers) and do not suffer from chronic ankle instability (CAI). This cross-sectional study involved 34 female athletes, who were classified into three groups (athletes with CAI, copers, and healthy athletes) and tested on a Biodex Balance System. Surface electromyography (EMG) and balance scores were monitored. The coper and healthy group exhibited higher medial gastrocnemius (MG) EMG activity during unstable balance conditions. The rectus abdominus (RA) in the coper group and rectus femoris (RF) in the healthy group showed greater EMG activity compared to CAI during unstable conditions. During stable conditions, the coper group showed greater RA EMG activity compared to CAI, as well as higher tibialis anterior (TA) EMG activity compared to the healthy group. Additionally, balance error scores were higher in the CAI group than those in the healthy gro...

Methodological Issues with Transcranial Direct Current Stimulation for Enhancing Muscle Strength and Endurance: A Narrative Review

Journal of Cognitive Enhancement, 2021

In recent years, there has been a substantial increase in the number of studies investigating the... more In recent years, there has been a substantial increase in the number of studies investigating the effects that transcranial direct current stimulation (tDCS) can have on exercise performance. Currently, there exists substantial conflict in the literature, with many studies reporting that 10–20 min of tDCS can result in augmented performance, while other studies also report no significant changes. Throughout the literature, there is considerable variance in the tDCS protocols being administered. These differences include electrode placement, stimulation intensity, stimulation duration, and participant’s sex. This variance may account for some of the discrepancies in the results of published studies. Therefore, the goal of this narrative review was to explore the differences in tDCS protocols among these studies to help determine which variations seem to be most effective at producing muscle strength and endurance performance increases. It is suggested that a standardized set of protocols would be beneficial in order to make the comparison of the literature more straightforward. Although, as it currently stands, more research in certain areas surrounding various tDCS variables is needed to determine the most optimal setup for increasing exercise performance.

Frontiers in Physiology, 2022

The objective of this study was to compare the activation of the core (trunk) musculature during ... more The objective of this study was to compare the activation of the core (trunk) musculature during quadriceps and hamstrings foam rolling (FR) vs. prone and supine/reverse static planks to determine if FR is a viable means of training the core musculature. Using a randomized allocation, nine recreationally trained, young adults (18–26 years) performed two sets each of quadriceps and hamstrings FR as well as supine/reverse and prone static planks for 30-s each with 1-min rest between sets and 5-min rest between exercises. Electromyographic (EMG) activity of the lower abdominals (LA), external obliques (EO), lumbosacral erector spinae (LSES), upper lumbar erector spinae (ULES) muscle groups were normalized to a maximum voluntary contraction and analyzed. Quadriceps FR exhibited a very large magnitude greater LA activity compared to reverse plank (p = 0.033, d = 4.42) and hamstrings FR (p = 0.020, d = 3.49), respectively. The prone plank demonstrated very large magnitude higher EO EMG ac...

International Journal of Environmental Research and Public Health, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Sports Medicine, 2021

Background: Unilateral fatigue and static stretching (SS) can impair performance and increase ran... more Background: Unilateral fatigue and static stretching (SS) can impair performance and increase range of motion of a non-exercised or non-stretched muscle respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective: The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature for future research. Methods: A systematic literature search following the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The Physiotherapy Evidence Database (PEDro) scale was used to assess study risk of bias and methodological quality. Results: Unilateral stretching protocols, from six studies, involved 6.3±2 repetitions of 36.3±7.4 seconds with 19.3±5.7 seconds recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-0.35: 0.01 to-1.8) and contralateral, non-stretched, muscles (-0.22: 0.08 to-1.1). Control measures exhibited trivial deficits. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others. Conclusion: The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude decrements in force output. However, the frequency of these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global effects of prolonged SS.

European Journal of Applied Physiology, 2021

Background: Static stretching (SS) can impair performance and increase range of motion of a nonex... more Background: Static stretching (SS) can impair performance and increase range of motion of a nonexercised or non-stretched muscle respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective: The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature. Methods: A systematic literature search following Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The Physiotherapy Evidence Database scale was used to assess study risk of bias and methodological quality. Results: Unilateral stretching protocols from six studies involved 6.3±2 repetitions of 36.3±7.4 seconds with 19.3±5.7 seconds recovery between stretches. The mean stretch-induced force deficits exhibited small magnitude effect sizes for both the stretched (-6.7±7.1%, d=-0.35: 0.01 to-1.8) and contralateral, non-stretched, muscles (-4.0±4.9%, d=-0.22: 0.08 to-1.1). Control measures exhibited trivial deficits. Conclusion: The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude force deficits. However, the frequency of studies with these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global (non-local) effects of prolonged SS. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others.

Applied Physiology, Nutrition, and Metabolism, 2019

Cross-education has been extensively investigated with adults. Adult studies report asymmetrical ... more Cross-education has been extensively investigated with adults. Adult studies report asymmetrical cross-education adaptations predominately after dominant limb training. The objective of the study was to examine unilateral leg press (LP) training of the dominant or nondominant leg on contralateral and ipsilateral strength and balance measures. Forty-two youth (10–13 years) were placed (random allocation) into a dominant (n = 15) or nondominant (n = 14) leg press training group or nontraining control (n = 13). Experimental groups trained 3 times per week for 8 weeks and were tested pre-/post-training for ipsilateral and contralateral 1-repetition maximum (RM) horizontal LP, maximum voluntary isometric contraction (MVIC) of knee extensors (KE) and flexors (KF), countermovement jump (CMJ), triple hop test (THT), MVIC strength of elbow flexors (EF) and handgrip, as well as the stork and Y balance tests. Both dominant and nondominant LP training significantly (p < 0.05) increased both ...

International Journal of Environmental Research and Public Health

Foam rolling (FR) is a new and popular technique for increasing range of motion. While there are ... more Foam rolling (FR) is a new and popular technique for increasing range of motion. While there are a few studies that demonstrate increased performance measures after an acute bout of FR, the overall evidence indicates trivial performance benefits. As there have been no meta-analyses on the effects of chronic FR on performance, the objective of this systematic meta-analytical review was to quantify the effects of FR training on performance. We searched PubMed, Scopus, the Cochrane library, and Web of Science for FR training studies with a duration greater than two weeks, and found eight relevant studies. We used a random effect meta-analysis that employed a mixed-effect model to identify subgroup analyses. GRADE analysis was used to gauge the quality of the evidence obtained from this meta-analysis. Egger’s regression intercept test (intercept 1.79; p = 0.62) and an average PEDro score of 6.25 (±0.89) indicated no or low risk of reporting bias, respectively. GRADE analysis indicated t...

Sports Medicine

Background Although it is known that resistance training can be as effective as stretch training ... more Background Although it is known that resistance training can be as effective as stretch training to increase joint range of motion, to date no comprehensive meta-analysis has investigated the effects of resistance training on range of motion with all its potential affecting variables. Objective The objective of this systematic review with meta-analysis was to evaluate the effect of chronic resistance training on range of motion compared either to a control condition or stretch training or to a combination of resistance training and stretch training to stretch training, while assessing moderating variables. Design For the main analysis, a random-effect meta-analysis was used and for the subgroup analysis a mixed-effect model was implemented. Whilst subgroup analyses included sex and participants’ activity levels, meta-regression included age, frequency, and duration of resistance training. Data Sources Following the systematic search in four databases (PubMed, Scopus, SPORTDiscus, an...

European Journal of Applied Physiology, 2022

Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the ran... more Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the range of motion (ROM) of a joint. However, possible differences in the magnitude of change on ROM between these two interventions on the immediate and prolonged effects (e.g., 10 min after the intervention) are not yet well understood. Thus, the purpose of this review was to compare the immediate and prolonged effects of a single bout of foam rolling with a single bout of stretching on ROM in healthy participants. Methods In total, 20 studies with overall 38 effect sizes were found to be eligible for a meta-analysis. For the main analysis, subgroup analysis, we applied a random-effect meta-analysis, mixed-effect model, respectively. The subgroup analyses included age groups, sex, and activity levels of the participants, as well as the tested muscles, the duration of the application, and the study design. Results Meta-analyses revealed no significant differences between a single stretching a...

European Journal of Applied Physiology, 2022

Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the ran... more Purpose Stretching and foam rolling are common warm-up exercises and can acutely increase the range of motion (ROM) of a joint. However, possible differences in the magnitude of change on ROM between these two interventions on the immediate and prolonged effects (e.g., 10 min after the intervention) are not yet well understood. Thus, the purpose of this review was to compare the immediate and prolonged effects of a single bout of foam rolling with a single bout of stretching on ROM in healthy participants. Methods In total, 20 studies with overall 38 effect sizes were found to be eligible for a meta-analysis. For the main analysis, subgroup analysis, we applied a random-effect meta-analysis, mixed-effect model, respectively. The subgroup analyses included age groups, sex, and activity levels of the participants, as well as the tested muscles, the duration of the application, and the study design. Results Meta-analyses revealed no significant differences between a single stretching a...

Journal of Sports Science and Medicine, Nov 24, 2015

JPHR: Journal of Performance Health Research, 2019

Background: Prolonged static stretching (SS) has been shown to impair subsequent performance of a... more Background: Prolonged static stretching (SS) has been shown to impair subsequent performance of a stretched muscle. There is evidence that unilateral SS can have crossover or global effects on range of motion (ROM), but there is scant information regarding whether prolonged SS also impairs the performance of contralateral muscle groups. Purpose: The objective of this study is to investigate the effects of self-administered unilateral SS with a TheraBand ® stretch strap on contralateral hip flexion ROM and knee extension isometric maximum voluntary contraction (MVC) force and muscle activation. Study Design: This study used an experimental repeated-measures intervention design. Methods: In total, 14 male participants performed self-administered SS of the dominant quadriceps and hamstrings (eight repetitions of 30 s each) with a TheraBand stretch strap. The aim was to observe pre-to post-SS-induced changes in hip flexion (hamstrings) ROM, knee extension (quadriceps) isometric force, and muscle activation (as recorded with electromyography [EMG]) in both dominant (experimental limb) and nondominant lower limbs (control lower limb). Results: A significant tested leg  time interaction [F (1,13) = 6.58; P = 0.04; eta 2 = 0.210) demonstrated that the ROM increases in both the stretched and contralateral nonstretched legs by 6.7% (d = 0.53) and 4.3% (d = 0.38), respectively. There were no significant interactions for MVC force or muscle activation for either leg. Conclusion: The lack of crossover MVC changes suggests that the mechanism for contralateral increases in ROM may be stretch tolerance. Clinical Relevance: Individuals who are injured or are undergoing rehabilitation should continue to stretch the noninjured limb to maintain or improve flexibility of the injured limb.

Journal of Strength and Conditioning Research, 2016

Balance training may have a preconditioning effect on subsequent power training with youth. There... more Balance training may have a preconditioning effect on subsequent power training with youth. There are no studies examining whether the sequencing of balance and plyometric training has additional training benefits. The objective was to examine the effect of sequencing balance and plyometric training on the performance of 12-13 years old athletes. Twenty-four young elite soccer players trained twice per week for eight weeks either with an initial four weeks of balance training followed by four weeks of plyometric training (BPT) or four weeks of plyometric training proceeded by four weeks of balance training (PBT). Testing was conducted pre-and post-training and included medicine ball throw, horizontal and vertical jumps, reactive strength, and leg stiffness, agility, 10, 20, 30-m sprints, Standing Stork balance test and Y-Balance Test. Results indicated that BPT provided significantly greater improvements with reactive strength index, absolute and relative leg stiffness, triple hop test (THT) and a trend for the Y balance test (p=0.054) compared to PBT. While all other measures had similar changes for both groups, the average relative improvement for the BPT was 22.4% (d= 1.5) versus 15.0% (d= 1.1) for the PBT. BPT effect sizes were greater with 8 of 13 measures. In conclusion, while either sequence of BPT or PBT improved jumping, hopping, sprint acceleration, and Standing Stork and Y balance; BPT initiated greater training improvements in reactive strength index, absolute and relative leg stiffness, THT and the Y balance test. BPT may provide either similar or superior performance enhancements compared to PBT.

European journal of applied physiology, 2015

Non-local muscle fatigue (NLMF) is characterized by muscle performance impairments in a contralat... more Non-local muscle fatigue (NLMF) is characterized by muscle performance impairments in a contralateral or remote non-exercised muscle(s) following a fatiguing protocol of a different muscle group(s). This topic is of interest as it affords insights into physiological determinants of muscle fatigue and may provide practical applications concerning the order of exercises in training and rehabilitation programs. A literature review was conducted using Web of Science, PubMed, and Google Scholar databases to evaluate the NLMF effects and possible underlying mechanisms. Overall, 35 studies with 58 outcome measures that met the inclusion criteria were identified. The literature is conflicting with approximately half of the studies reporting NLMF effects (32 of 58 measurements). However, on closer examination 76% of outcome measures of the lower limbs reported NLMF effects (23 of 30 measurements) compared to only 32% in the upper body (9 of 28 measurements). Thus, it appears that NLMF effect...

International journal of sports physical therapy, 2015

The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically... more The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically reported to accentuate the subsequent concentric jump performance. Some researchers have rationalized that adding elastic resistance (ER) to explosive type activities (e.g. countermovement jumps and drop jumps) would increase excitatory stretch reflex activity and mechanical recoil characteristics of the musculotendinous tissues. The purpose of this meta-analysis was to examine the available literature on jumping movements augmented with ER and to provide a quantitative summary on the effectiveness of this technique for enhancing acute eccentric and concentric jumping performance. In a random-effects model, the Hedges`s g effect size (ES) was used to calculate the biased corrected standardized mean difference between the augmented and similar non-augmented jumps. The results demonstrated that augmented jumps provided a greater eccentric loading compared to free jumps (Hedges`s g ES = 0....

European Journal of Applied Physiology, 2015

Haddad JSCR 2013 Static Stretching Can Impair Explosive Performance For At Least 24 Hours

PLOS ONE, 2015

Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for y... more Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration) curve. Two groups of eight undergraduate students (n = 16) took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD) drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV)). Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third asessement. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sentitive enough to predict crash risk for young drivers, even when intoxicated.