- Dr. Behm has worked at Memorial University of Newfoundland since 1995 teaching more than 18 different courses and ser... moreDr. Behm has worked at Memorial University of Newfoundland since 1995 teaching more than 18 different courses and served as Associate Dean of the School of Human Kinetics and Recreation Graduate Studies for approximately 10 years. His research interests have been diverse with over 270 peer-reviewed articles, and over 16000 citations (h index of 63 with 60 classified as truly exceptional) exploring neuromuscular responses to stretching, resistance training, balance, fatigue, and other topics. David has authored a number of chapters and a book entitled “The Science and Physiology of Flexibility and Stretching: Implications and Applications in Sport Performance and Health” (Routledge Publishers 2018). He has received a number of university, national and international awards such as the National Strength and Conditioning Association Outstanding Sport Scientist award (2014) and Canadian Society for Exercise Physiology Honour Award (2015).edit
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... 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...
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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... 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...
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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... 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.
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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... 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...
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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)... 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 ...
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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... 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...
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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... 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...
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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... 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...
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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... 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...
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Research Interests: Soccer, Plyometrics, Running, Adolescent, Medicine, and 13 moreBiomechanics of strength and conditioning, Muscle strength, Humans, Child, Strength and Conditioning, Male, Sport Science, Acceleration, Athletic performance, Postural Balance, Exercise Test, Plyometric exercise, and Sports Science Research
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... 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...
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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... 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....
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Research Interests: Psychology, Perception, Martial Arts, Adolescent, Medicine, and 8 moreSports, Humans, Child, Male, Heart rate, Exercise, Athletes, and physical exertion
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ABSTRACT This chapter presents two common objective methods based on heart rate (HR) for monitoring training load (TL) in Taekwondo (TKD). A model is proposed for monitoring TL, overtraining, recovery and upper respiratory infection in... more
ABSTRACT This chapter presents two common objective methods based on heart rate (HR) for monitoring training load (TL) in Taekwondo (TKD). A model is proposed for monitoring TL, overtraining, recovery and upper respiratory infection in TKD with simple and practical methods such as rating of perceived exertion (RPE), Hooper Index (ratings for the quality of sleep, quantity of fatigue, sleep and delayed onset muscle soreness [DOMS]), Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21) questionnaire and total quality recovery (TQR).
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Research Interests: Psychology and Medicine
There were two major objectives for this thesis: 1) to integrate the existing literature based on vigilance, noise, and neuromuscular fatigue and 2) to determine the effects of muscle contraction intensity, neuromuscular fatigue, and... more
There were two major objectives for this thesis: 1) to integrate the existing literature based on vigilance, noise, and neuromuscular fatigue and 2) to determine the effects of muscle contraction intensity, neuromuscular fatigue, and noise on the performance of complex and simple vigilance tasks. Vigilance or an individual's state of physiological or psychological readiness to mediate performance when reacting to a stimulus can be affected simultaneously by noise and neuromuscular stimuli. Noise exposure and muscle contraction have been shown to both negatively and positively affect vigilance performance. However, this contradiction may be a result of differences in muscle contraction and noise intensities, durations, and type as well as the complexity of the vigilance task. It was determined in the present experiment that continuous noise at an intensity of 95 dB (A) impairs both simple and to a greater extent complex vigilance task performance. Isometric muscle contractions at 5% and 20% of a maximum voluntary contraction also impaired simple and complex vigilance task performance. There did not seem to be an interaction effect between noise and contraction intensity.
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This study examined the effect of the handball warm-up program (HWP) on dynamic balance among elite adolescent handball players. In this case, 24 handball players were randomly assigned into experimental warm-up and control groups. The... more
This study examined the effect of the handball warm-up program (HWP) on dynamic balance among elite adolescent handball players. In this case, 24 handball players were randomly assigned into experimental warm-up and control groups. The HWP was performed over 8 weeks (3 times per week). Dynamic balance before and after the intervention training programs were measured by the Biodex Balance System (BBS) and Y Balance test for the dominant (DL) and non-dominant legs (non-DL). After HWP training, BBS scores significantly improved in the overall (OSI) (30.4% and 31.1%), anterior-posterior (APSI) (44.6% and 35.2%), and medial-lateral stability indexes (MLSI) (38.8% and 43%) for both DL and non-DL. Post-training, the Y Balance test exhibited significant improvements in OSI (13.2% and 10.6%), anterior (17.2% and 12.6%), posteriolateral (12.8% and 11.3%), and posteriomedial stability indexes (9.2% and 7.9%) with DL and non-DL, respectively. In conclusion, dynamic balance improved overall afte...
Research Interests: Sports Medicine, Sports Injuries, Sport Biomechanics, Sports Biomechanics, Handball, and 11 moreSport, Sports, Sports Coaching, Sports Injury, Sports Coaching and Training, Risk factors, Risk Factors, Postural Balance, Kinesiology and Sports Science, Sports Medicine and Rehabilitation, and Medicine and Science In Sports and Exercise
Previous studies have demonstrated that an acute bout of static stretching may cause significant performance impairments. However, there are no studies investigating the effect of prolonged stretch training on stretch-induced decrements.... more
Previous studies have demonstrated that an acute bout of static stretching may cause significant performance impairments. However, there are no studies investigating the effect of prolonged stretch training on stretch-induced decrements. It was hypothesized that individuals exhibiting a greater range of motion (ROM) in the correlation study or those who attained a greater ROM with flexibility training would experience less stretch-induced deficits. A correlation study had 18 participants (25 ± 8.3 years, 1.68 ± 0.93 m, 73.5 ± 14.4 kg) stretch their quadriceps, hamstrings and plantar flexors three times each for 30 s with 30 s recovery. Subjects were tested pre- and post-stretch for ROM, knee extension maximum voluntary isometric contraction (MVIC) force and drop jump measures. A separate training study with 12 subjects (21.9 ± 2.1 years, 1.77 ± 0.11 m 79.8 ± 12.4 kg) involved a four-week, five-days per week, flexibility training programme that involved stretching of the quadriceps, ...
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Most studies have examined pacing strategies with cyclical activities (running and cycling). It has been demonstrated that males employ different pacing strategies during repeated maximal voluntary contractions (MVCs) dependent upon a... more
Most studies have examined pacing strategies with cyclical activities (running and cycling). It has been demonstrated that males employ different pacing strategies during repeated maximal voluntary contractions (MVCs) dependent upon a known endpoint. Since different fatiguing mechanisms have been identified between the genders, it is not known if females use comparable pacing strategies. The purpose of this study was to examine if informing female subjects regarding the number of MVCs to perform would affect force and electromyography (EMG). Twenty well-trained females completed 3 fatiguing protocols in a randomized order. In the control condition participants were informed they would perform twelve MVCs and then actually completed twelve. In the unknown condition they were not told how many MVCs to perform but were stopped after twelve. In the deception condition they were initially informed to perform 6 MVCs, but after the 6(th) MVC they were asked to perform a few more MVCs and w...
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Roller massagers are popular devices that are used to improve range of motion (ROM), enhance recovery from muscle soreness, and reduce pain under acute conditions. However, the effects of roller massage training and training frequency are... more
Roller massagers are popular devices that are used to improve range of motion (ROM), enhance recovery from muscle soreness, and reduce pain under acute conditions. However, the effects of roller massage training and training frequency are unknown. The objective was to compare two different roller massage training frequencies on muscle performance. Randomized controlled intervention study. Twenty-three recreationally active university students were randomly allocated to three groups: control (n=8;), rolling three (3/W; n=8;) and six (6/W; n=7) times per week for four weeks. The roller massage training consisted of unilateral, dominant limb, quadriceps and hamstrings rolling (4 sets x 30 seconds). Both legs of participants were tested pre- and post-training for active and passive hamstrings and quadriceps range of motion (ROM), electromyography (EMG) activity during a lunge movement, unilateral countermovement jumps (CMJ), as well as quadriceps and hamstrings maximum voluntary isometr...
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A new testing procedure is introduced to evaluate the alactic running performance in a 10s sprint task with near-maximal movement velocity. The test is performed on a motor-equipped treadmill with inverted polarity that increases... more
A new testing procedure is introduced to evaluate the alactic running performance in a 10s sprint task with near-maximal movement velocity. The test is performed on a motor-equipped treadmill with inverted polarity that increases mechanical resistance instead of driving the treadmill belt. As a result, a horizontal force has to be exerted against the treadmill surface in order to overcome the resistant force of the engine and to move the surface in a backward direction. For this task, subjects lean with their hands towards the front safety barrier of the treadmill railing with a slightly inclined body posture. The required skill resembles the pushing movement of bobsleigh pilots at the start of a race. Subjects are asked to overcome this mechanical resistance and to cover as much distance as possible within a time period of 10 seconds. Fifteen male students (age: 27.7 ± 4.1 years, body height: 1.82 ± 0.46 m, body mass: 78.3 ± 6.7 kg) participated in a study. As the resistance force ...
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The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally... more
The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally active females were tested pre- and post-training (fixed foot balance training, n= 11, functionally directed balance training, n = 7 and control group, n = 6). Experimental subjects completed either fixed foot or functionally directed balance exercises 4 times/week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings following a jump. Maximum vertical jump height, static balance and 20-meter sprint times were also examined. The fixed foot balance-training group showed a 33% improvement (p < 0.05) in static balance time and 9% improvement in jump height. Neither type of training improved sprint times. ...
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Currently there are recommendations for stretching type, repetitions and duration within a training session to improve flexibility. It is, however, unclear whether multiple daily stretch training sessions provide greater flexibility than... more
Currently there are recommendations for stretching type, repetitions and duration within a training session to improve flexibility. It is, however, unclear whether multiple daily stretch training sessions provide greater flexibility than single daily sessions. The objective was to investigate the effectiveness of single (1×day) versus twice daily (2×day) unilateral stretch training sessions on hip flexion range of motion (ROM), agonist and antagonist force and jump performance of the stretched and contralateral, non-stretched legs. Groups included a control, 1×day and 2×day stretch training groups. Static stretching (SS) involved self-administered (stretch band), unilateral, hamstrings and quadriceps stretching for 2-weeks. Pre- and post-testing involved hip flexion ROM, knee extension and flexion maximal voluntary isometric contraction (MVIC) forces and unilateral drop jumps (DJ). The 2×day group showed a 12.8% (p = 0.08) greater active ROM versus Control. The 1×day group showed a ...
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The construct and concurrent validity of the Thera-Band Perceived Exertion Scale for Resistance Exercise with elastic bands (EB) was examined. Twenty subjects performed two separate sets of 15 repetitions of both frontal and lateral raise... more
The construct and concurrent validity of the Thera-Band Perceived Exertion Scale for Resistance Exercise with elastic bands (EB) was examined. Twenty subjects performed two separate sets of 15 repetitions of both frontal and lateral raise exercise over two sessions. The criterion variables were myoelectric activity and heart rate. One set was performed with an elastic band grip width that permitted 15 maximum repetitions in the selected exercise, and another set was performed with a grip width 50% more than the 15RM grip. Following the final repetition of each set, active muscle (AM) and overall body (O) ratings of perceived exertion (RPE) were collected from the Thera-Band® resistance exercise scale and the OMNI-Resistance Exercise Scale of perceived exertion with Thera-Band® resistance bands (OMNI-RES EB). Construct validity was established by correlating the RPE from the OMNI-RES EB with the Thera-Band RPE scale using regression analysis. The results showed significant difference...
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Push-ups are an ubiquitous resistance training exercise. While exhibiting a relatively similar upper body motion to the bench press, there are substantial differences in repetitions when employing similar relative loads. The objective was... more
Push-ups are an ubiquitous resistance training exercise. While exhibiting a relatively similar upper body motion to the bench press, there are substantial differences in repetitions when employing similar relative loads. The objective was to examine sex-related differences in repetitions and muscle activation associated with push-ups and bench press exercises. Twenty resistance-trained participants (10 men [22 ± 6.1 years] and 10 [24 ± 5.7 years] women) performed maximum push-up and bench press repetitions with loads relative to the body mass during a push-up. Electromyographic (EMG) electrodes were positioned on the middle and anterior deltoids, triceps and biceps brachii, and pectoralis major muscles and their relative (normalized to a maximum voluntary contraction) activity was compared between the two exercises performed to task failure. Both females (3.5 ± 3.9 vs.15.5 ± 8.0 repetitions; p = 0.0008) and males (12.0 ± 6.3 vs. 25.6 ± 5.2 repetitions; p < 0.0001) performed 77.4%...
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The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (SS) on the passive range of movement (ROM) of the stretched limb, surface electromyography (sEMG) and single-leg bounce drop... more
The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (SS) on the passive range of movement (ROM) of the stretched limb, surface electromyography (sEMG) and single-leg bounce drop jump (SBDJ) performance measures of the ipsilateral stretched and contralateral non-stretched lower limbs. Seventeen young men (24 ± 5 years) performed SBDJ before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) unilateral ankle plantar flexor SS (6 sets of 45s/15s, 70-90% point of discomfort). SBDJ performance measures included jump height, impulse, time to reach peak force, contact time as well as the sEMG integral (IEMG) and pre-activation (IEMGpre-activation) of the gastrocnemius lateralis. Ankle dorsiflexion passive ROM increased in the stretched limb after the SS (pre-test: 21 ± 4° and post-test: 26.5 ± 5°, p < 0.001). Post-stretching decreases were observed with peak fo...
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The purpose of this study was to investigate different intensities of unilateral fatiguing dynamic quadriceps contractions on non-exercised, contralateral quadriceps performance. In a randomized crossover study design with 12... more
The purpose of this study was to investigate different intensities of unilateral fatiguing dynamic quadriceps contractions on non-exercised, contralateral quadriceps performance. In a randomized crossover study design with 12 recreationally trained male (1.78 ± 0.05 m, 84.5 ± 7.6 kg, 30.0 ± 8.5 yrs) participants, maximal voluntary contraction (MVC) force, force developed in the first 100 ms (F100), and electromyography of the non-exercised contralateral knee extensors were measured before and after fatiguing protocols performed by ipsilateral knee extensors. Non-exercised knee extensors' endurance was also measured post-intervention. The fatigue protocols consisted of four sets of dynamic knee extensions each to task failure with 40% and 70% MVC on separate days. Both the 40% (p = 0.009, Effect Size [ES] = 0.72) and 70% (p = 0.001, ES = 2.03) conditions exhibited 23.7% and 34.6% decreases in F100 respectively with the non-exercised contralateral knee extensors. A significant tim...
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PURPOSE/BACKGROUND Pain can adversely affect muscle functioning by inhibiting muscle contractions. Delayed onset muscle soreness was used as a tool to ascertain whether a topical menthol-based analgesic or ice was more effective at... more
PURPOSE/BACKGROUND Pain can adversely affect muscle functioning by inhibiting muscle contractions. Delayed onset muscle soreness was used as a tool to ascertain whether a topical menthol-based analgesic or ice was more effective at reducing pain and permitting greater muscular voluntary and evoked force. METHODS Sixteen subjects were randomized to receive either a topical gel containing 3.5% menthol or topical application of ice to the non-dominant elbow flexors two days following the performance of an exercise designed to induce muscle soreness. Two days later, DOMS discomfort was treated with a menthol based analgesic or ice. Maximum voluntary contractions and evoked tetanic contractions of the non-dominant elbow flexors were measured at baseline prior to inducing muscle soreness (T1), two days following inducing DOMS after 20 (T2), 25 (T3) and 35 (T4) minutes of either menthol gel or ice therapy. Pain perception using a 10-point visual analog scale was also measured at these four...
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While muscle stretching has been commonly used to alleviate pain, reports of its effectiveness are conflicting. The objective of this review is to investigate the acute and chronic effects of stretching on pain, including delayed onset... more
While muscle stretching has been commonly used to alleviate pain, reports of its effectiveness are conflicting. The objective of this review is to investigate the acute and chronic effects of stretching on pain, including delayed onset muscle soreness. The few studies implementing acute stretching protocols have reported small to large magnitude decreases in quadriceps and anterior knee pain as well as reductions in headache pain. Chronic stretching programs have demonstrated more consistent reductions in pain from a wide variety of joints and muscles, which has been ascribed to an increased sensory (pain) tolerance. Other mechanisms underlying acute and chronic pain reduction have been proposed to be related to gate control theory, diffuse noxious inhibitory control, myofascial meridians, and reflex-induced increases in parasympathetic nervous activity. By contrast, the acute effects of stretching on delayed onset muscle soreness are conflicting. Reports of stretch-induced reductio...
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The objective was to investigate the effects of functional (FT) and traditional (TT) training on trunk muscles maximal isometric strength, rate of force development and endurance with trained elderly women. Forty-five elderly women were... more
The objective was to investigate the effects of functional (FT) and traditional (TT) training on trunk muscles maximal isometric strength, rate of force development and endurance with trained elderly women. Forty-five elderly women were directed into three groups: FT (n =1 6), TT (n = 14) and Control (n = 15). The FT (multi-planar, and multi-articular movements) and TT (primarily machine-based resistance exercises) performed mobility, muscle strength and power exercises. Both training groups also performed intermittent cardiometabolic activities. The maximum strength and endurance of the trunk muscles were verified, both at baseline and after 12 weeks of training (3xweek for 50 min each). Data were analyzed using a 2-way ANCOVA with contrast of adjusted mean values. FT significantly increased all variables: maximum trunk flexor strength (p = 0.002, 22%); rate of flexor force development (p = 0.001, 84%); trunk extensors maximal strength (p = 0.003, 17%); trunk extensor rate of force...
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Increased stretch tolerance can contribute to improved range of motion (ROM). Since menthol-based topical analgesics (TopAnalg) suppress pain, they may increase stretch thresholds improving ROM. Other modalities such as transcutaneous... more
Increased stretch tolerance can contribute to improved range of motion (ROM). Since menthol-based topical analgesics (TopAnalg) suppress pain, they may increase stretch thresholds improving ROM. Other modalities such as transcutaneous electrical nerve stimulation and rolling have demonstrated decreased pain sensitivity in the contralateral limb. The purpose of this study was to investigate the effects of a TopAnalg on active and passive ROM of the treated and contralateral (untreated) leg. With a double blind, repeated measures design, 14 university students had a TopAnalg or a placebo gel applied to their hamstrings, rested for 20-min and then either performed static or dynamic stretching. Prior to gel application and after stretching, participants were tested for passive static, active and ballistic hip flexion ROM. Near significant greater ballistic hip flexion ROM for both legs (treated: p = 0.08; 3.6%; contralateral: p = 0.1; 1.6%) were observed with the TopAnalg. With dynamic ...
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Non-local muscle fatigue (NLMF) studies have examined crossover impairments of maximal voluntary force output in non-exercised, contralateral muscles as well as comparing upper and lower limb muscles. Since prior studies primarily... more
Non-local muscle fatigue (NLMF) studies have examined crossover impairments of maximal voluntary force output in non-exercised, contralateral muscles as well as comparing upper and lower limb muscles. Since prior studies primarily investigated contralateral muscles, the purpose of this study was to compare NLMF effects on elbow flexors (EF) and plantar flexors (PF) force and activation (electromyography: EMG). Secondly, possible differences when testing ipsilateral or contralateral muscles with a single or repeated isometric maximum voluntary contractions (MVC) were also investigated. Twelve participants (six males: (27.3 ± 2.5 years, 186.0 ± 2.2 cm, 91.0 ± 4.1 kg; six females: 23.0 ± 1.6 years, 168.2 ± 6.7 cm, 60.0 ± 4.3 kg) attended six randomized sessions where ipsilateral or contralateral PF or EF MVC force and EMG activity (root mean square) were tested following a dominant knee extensors (KE) fatigue intervention (2×100s MVC) or equivalent rest (control). Testing involving a s...
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Post-activation potentiation (PAP) conditioning has been reported to increase performance. Most research has examined PAP effects on strength/power activities, whereas the effects on endurance sports are understudied. The aim of this... more
Post-activation potentiation (PAP) conditioning has been reported to increase performance. Most research has examined PAP effects on strength/power activities, whereas the effects on endurance sports are understudied. The aim of this study was to characterize PAP conditioning stimulus effects on a subsequent 5x1 km running trial. A randomized, within subjects, repeated measures study utilized 12 male, endurance-trained athletes, who performed a full warm-up, conditioning exercise intervention (4x5 repetition maximum band-resisted squat jumps) or a control condition prior to a 5x1 km time trial run. Tests were conducted immediately prior to the intervention, after each kilometer, immediately following the 5x1 km run, and at seven and ten minutes post 5 km run. Measures included the interpolated twitch technique (ITT), evoked contractile properties, maximum voluntary isometric contractions (MVIC) plantar flexor force, drop jump, rating of perceived exertion, and heart rate. The PAP st...
Research Interests:
Background: Eccentric resistance training (ERT) in youth is advocated for aiding performance and injury risk. However, research investigating the applied practices of ERT in youth is in its infancy. In this study, we surveyed the... more
Background: Eccentric resistance training (ERT) in youth is advocated for aiding performance and injury risk. However, research investigating the applied practices of ERT in youth is in its infancy. In this study, we surveyed the perceptions and practices of practitioners utilizing ERT in youth to provide an understanding of its current application in practice. Methods: Sixty-four strength and conditioning coaches completed an online survey reporting their current use of ERT in youth using both open and closed questions. Results: Coaches deemed the inclusion of ERT important in youth with its inclusion based upon factors such as maturation status, training age and strength levels. Coaches also displayed an awareness of the physiological responses to eccentric exercise in youth compared to adults. ERT was primarily used for injury prevention, with the majority of coaches using body-weight and tempo exercises. Furthermore, utilizing eccentric hamstrings exercises was reported as highl...
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The integration of balance and plyometric training has been shown to provide significant improvements in sprint, jump, agility, and other performance measures in young athletes. It is not known if a specific within session balance and... more
The integration of balance and plyometric training has been shown to provide significant improvements in sprint, jump, agility, and other performance measures in young athletes. It is not known if a specific within session balance and plyometric exercise sequence provides more effective training adaptations. The objective of the present study was to investigate the effects of using a sequence of alternating pairs of exercises versus a block (series) of all balance exercises followed by a block of plyometric exercises on components of physical fitness such as muscle strength, power, speed, agility, and balance. Twenty-six male adolescent soccer players (13.9 ± 0.3 years) participated in an 8-week training program that either alternated individual balance (e.g., exercises on unstable surfaces) and plyometric (e.g., jumps, hops, rebounds) exercises or performed a block of balance exercises prior to a block of plyometric exercises within each training session. Pre- and post-training mea...
Research Interests:
Post-activation performance enhancement (PAPE) is an improvement to voluntary muscle performance following a conditioning activity. There is evidence of fatigue resistance deficits in non-exercised muscles following unilateral fatiguing... more
Post-activation performance enhancement (PAPE) is an improvement to voluntary muscle performance following a conditioning activity. There is evidence of fatigue resistance deficits in non-exercised muscles following unilateral fatiguing exercise of a contralateral muscle. The purpose of this study was to determine if a unilateral conditioning exercise protocol could induce PAPE in a contralateral, non-exercised muscle in young healthy adults. Thirty-two recreationally trained (n = 16) and athletically trained (n = 16) participants (16 males; age: 22.9 ± 2.03 years; height: 1.81 ± 0.06 m; weight: 82.8 ± 9.43 kg, and 16 females; age: 23.1 ± 2.80 years; height: 1.67 ± 0.07 m; weight: 66.4 ± 11.09 kg) were randomly allocated into two groups (dominant or non-dominant limb intervention). The experimental intervention, involved a conditioning exercise (4-repetitions of 5-seconds knee extension maximal voluntary isometric contractions: MVIC) with either the dominant (DOM) (n = 16) or non-do...
Balance as a skill and task-specific capacity is considered an essential physical quality in curling, required for executing effective stone delivery. However, no testing protocols have been developed to test curling-specific balance in... more
Balance as a skill and task-specific capacity is considered an essential physical quality in curling, required for executing effective stone delivery. However, no testing protocols have been developed to test curling-specific balance in the delivery position. Thus, the primary aim of this study was to investigate the reliability, validity and usefulness of a newly-developed, curling-specific balance test (CSBT) which involved the delivery position. The secondary aim was to examine the differences between elite and sub-elite curlers for core strength and flexibility, which have previously been identified as important qualities in curling and determinants of balance. Twenty curling players (13 females aged 19 ± 3.1 years; 7 males aged 19.6 ± 2.3 years) from five Swedish super-league curling clubs were divided into two groups according to playing level: elite and sub-elite. Variables included body mass, body height, body mass index, age, playing experience, training frequency, plank te...