Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol in... more Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or m...
International Journal of Sports Physiology and Performance, 2021
Purpose: To investigate the relationships between internal and external training load (TL) metric... more Purpose: To investigate the relationships between internal and external training load (TL) metrics with elite international women’s basketball performance. Methods: Sessional ratings of perceived exertion, PlayerLoad™/minute, and training duration were collected from 13 elite international-level female basketball athletes (age 29.0 [3.7] y, stature 186.0 [9.8] cm, body mass 77.9 [11.6] kg) during the 18 weeks prior to the International Basketball Federation Olympic qualifying event for the 2016 Rio Olympic Games. Training stress balance, differential load, and the training efficiency index were calculated with 3 different smoothing methods. These TL metrics and their change in the last 21 days prior to competition were examined for their relationship to competition performance as coach ratings of performance. Results: For a number of TL variables, there were consistent significant small to moderate correlations with performance and significant small to large differences between succ...
Mixed martial arts (MMA) is a combat sport underpinned by techniques from other combat discipline... more Mixed martial arts (MMA) is a combat sport underpinned by techniques from other combat disciplines, in addition to strategies unique to the sport itself. These sports can be divided into two distinct categories (grappling or striking) based on differing technical demands. Uniquely, MMA combines both methods of combat and therefore appears to be physiologically complex requiring a spectrum of mechanical and metabolic qualities to drive performance. However, little is known about the physiological characteristics that distinguish higher- from lower-level MMA athletes. Such information provides guidance for training interventions, performance testing and talent identification. Furthermore, while MMA incorporates techniques from both grappling and striking sports, it is unknown precisely how these disciplines differ physiologically. Understanding the relationship between higher-level competitors in grappling and striking combat sports can provide further insight into the development of ...
Applied Physiology, Nutrition, and Metabolism, 2016
The purpose of this study was to examine the relationships between maximal voluntary postactivati... more The purpose of this study was to examine the relationships between maximal voluntary postactivation potentiation (PAP) and maximal knee extensor torque, quadriceps cross-sectional area (CSA) and volume, and type II myosin heavy chain (MHC) isoform percentage in human skeletal muscle. Thirteen resistance-trained men completed a test protocol consisting of 2 isokinetic knee extensions at 180°·s–1performed before and 1, 4, 7, and 10 min after the completion of 4 maximal knee extensions at 60°·s–1(i.e., a conditioning activity (CA)). Magnetic resonance imaging and muscle microbiopsy procedures were completed on separate days to assess quadriceps CSA and volume and MHC isoform content. Maximal voluntary PAP response was assessed as the ratio of the highest knee extensor torques measured before and after the CA. There were large to very large correlations between maximal voluntary PAP response and maximal knee extensor torque (r = 0.62) and quadriceps CSA (r = 0.68) and volume (r = 0.63)....
SUMMARY THIS RESEARCH BRIEF COVERS CONCURRENT STRENGTH AND ENDURANCE TRAINING IN ELITE SOCCER PLA... more SUMMARY THIS RESEARCH BRIEF COVERS CONCURRENT STRENGTH AND ENDURANCE TRAINING IN ELITE SOCCER PLAYERS, THE EFFECT OF HYPERTROPHY TRAINING PROTOCOLS WITH MAXIMAL LOADING ON NEURAL DRIVE, THE EFFECT OF CLUSTER SETS ON POWER IN JUMP SQUATS, AND THE EFFECT OF AGE ON REPEATED-SPRINT ABILITY IN YOUTH SOCCER PLAYERS.
International Journal of Sports Physiology and Performance, 2018
Purpose: To examine the reliability of peak velocity (PV), mean propulsive velocity (MPV), and me... more Purpose: To examine the reliability of peak velocity (PV), mean propulsive velocity (MPV), and mean velocity (MV) in the development of load–velocity profiles (LVP) in the full-depth free-weight back squat performed with maximal concentric effort. Methods: Eighteen resistance-trained men performed a baseline 1-repetition maximum (1-RM) back-squat trial and 3 subsequent 1-RM trials used for reliability analyses, with 48-h intervals between trials. 1-RM trials comprised lifts from 6 relative loads including 20%, 40%, 60%, 80%, 90%, and 100% 1-RM. Individualized LVPs for PV, MPV, or MV were derived from loads that were highly reliable based on the following criteria: intraclass correlation coefficient (ICC) >.70, coefficient of variation (CV) ≤10%, and Cohen d effect size (ES) <0.60. Results: PV was highly reliable at all 6 loads. MPV and MV were highly reliable at 20%, 40%, 60%, 80%, and 90% but not 100% 1-RM (MPV: ICC = .66, CV = 18.0%, ES = 0.10, SEM = 0.04 m·s−1; MV: ICC = .5...
The primary objective of this investigation was to investigate the relationships between training... more The primary objective of this investigation was to investigate the relationships between training load (TL), heart rate variability (HRV) and direct current potential (DC) with elite long jump performance prior to and during the 2016 Olympics Games. Sessional ratings of perceived exertion (sRPE), training duration, HRV and DC were collected from four elite athletes (26.4 ± 1.4 years, height 1.83 ± 0.05 m, weight 68.9 ± 5.0 kg) for a 16-week period in qualification for and competition at the 2016 Olympic Games. Acute and chronic TL, training stress balance and differential load were calculated with three different smoothing methods. These TL measures along with HRV and DC were examined for their relationship to intra-athlete performance using repeated measure correlations and linear mixed models. Successful compared to unsuccessful intra-athlete performances were characterised by a higher chronic TL (p < 0.01, f2 = 0.31) but only when TL was exponentially smoothed. There were also...
Introduction: Conceptually, it is important to understand the underlying physiological mechanisms... more Introduction: Conceptually, it is important to understand the underlying physiological mechanisms of any training program model. This understanding aids the coach/sport scientist in making better choices in manipulating variables in formulating the training model. These underlying mechanisms can be associated with training variable manipulation, fatigue management aspects and the overall health of the athlete. Hormone and cytokine concentrations can be linked to alterations resulting from the manipulation of training variables and to subsequent alterations in performance. For example, alterations in the testosterone: cortisol ratio (T:C) has been associated with alterations in training volume as well as physiological aspects such as lean body mass, fat content and strength/power performance. Although cytokine production is part of the adaptive process, markedly increased/excessive cytokine production has been related poor fatigue management and over training. Purpose: The purpose of this study was to investigate the alterations and relationships among training variables, and physiological variables. Subjects: Nine (9) D-1 collegiate throwers and 4 control subjects participated in the study. Methods: The throwers participated in an 11- week periodized resistance training and throws program. Volume load was recorded throughout the study. Hormone (testosterone and cortisol (C), and adipokine (adiponectin, leptin, and resistin) measurements were taken at weeks 1, 7, and 11 for the throwers. Results: Hormone values did not exhibit statistically significant changes across time; however, there were trends across time for C, the T:C ratio and adiponectin. Conclusions: Based on the hormonal and adipokine data, it appears that the training program produced some positive effects. These effects indicate a reasonable degree of fatigue management in that C decreased and the T:C ratio was increased as volume load decreased. Literature supports the idea that increases in adiponectin may be a positive outcome of a sound training protocol (Smith et al., 2000). The present observation indicates that adiponectin increased in concert with decreases in C and increases in the T:C. ratio. Considering the effects of these hormones and cytokines, these alterations over time indicate a lesser degree of obesity related inflammation and a higher degree of “fitness” and preparednes
The purpose of this investigation was to determine the acute effects of back squats on countermov... more The purpose of this investigation was to determine the acute effects of back squats on countermovement jump performance across multiple sets using a strength-power potentiation complex training protocol. Fifteen elite volleyball players performed three unloaded countermovement jumps (CMJ) following three repetitions of the back squat performed at either 65% or 87% of 1-RM, respectively, repeated for 10 sets. A control session of three CMJs was also repeated for 10 sets. Mean jump height performance was enhanced compared to performing CMJs only irrespective of which intensity was used (65% 1-RM: +3.3 ± 2.2% [CI: 1.0 to 5.6]; 87% 1-RM: 2.6 ± 1.9% [CI: 0.7 to 4.5]). Subjects with a greater relative strength possessed a very likely large (97%; ES = 1.51) chance of improvement in jump height across 10 sets of the protocol prescribed using the intensity of 87% 1-RM and a likely moderate (89%; ES = 0.94) and very likely large (97%; ES = 1.76) chance of improvement in maximum concentric imp...
Journal of Functional Morphology and Kinesiology, 2019
The purpose of this review was to provide a physiological rationale for the use of eccentric resi... more The purpose of this review was to provide a physiological rationale for the use of eccentric resistance training and to provide an overview of the most commonly prescribed eccentric training methods. Based on the existing literature, there is a strong physiological rationale for the incorporation of eccentric training into a training program for an individual seeking to maximize muscle size, strength, and power. Specific adaptations may include an increase in muscle cross-sectional area, force output, and fiber shortening velocities, all of which have the potential to benefit power production characteristics. Tempo eccentric training, flywheel inertial training, accentuated eccentric loading, and plyometric training are commonly implemented in applied contexts. These methods tend to involve different force absorption characteristics and thus, overload the muscle or musculotendinous unit in different ways during lengthening actions. For this reason, they may produce different magnitu...
Journal of strength and conditioning research, 2018
Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and bet... more Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and between-session reliability of the isometric midthigh pull in young female athletes. J Strength Cond Res 32(7): 1892-1901, 2018-To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre- and post-peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation ...
International journal of sports medicine, Jan 21, 2018
The aim of this study was to compare three specific concentric and eccentric muscle action traini... more The aim of this study was to compare three specific concentric and eccentric muscle action training protocols on quadriceps-hamstrings neuromuscular adaptations. Forty male volunteers performed 6 weeks of training (two sessions/week) of their dominant and non-dominant legs on an isokinetic dynamometer. They were randomly assigned to one of four groups; concentric quadriceps and concentric hamstrings (CON/CON, n=10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n=10), concentric quadriceps and eccentric hamstrings (CON/ECC, n=10), or no training (CTRL, n=10). Intensity of training was increased every week by decreasing the angular velocity for concentric and increasing it for eccentric groups in 30°/s increments. Volume of training was increased by adding one set every week. Dominant leg quadriceps and hamstrings muscle thickness, muscle quality, muscle activation, muscle coactivation, and electromechanical delay were tested before and after training. Results revealed that...
International journal of sports physiology and performance, Jan 28, 2017
This investigation examined the reliability and usefulness of the isometric mid-thigh pull (IMTP)... more This investigation examined the reliability and usefulness of the isometric mid-thigh pull (IMTP) and isometric squat (ISqT) performed at the same knee and hip angles. The scores produced in each test were compared to determine the magnitude of differences between tests. Twenty six male and female athletes (23.6±4.3 y; 1.75±0.07 m; 68.8±9.7 kg) performed 2 maximal repetitions of the IMTP and ISqT following a specific warm up. Maximum force, absolute peak force (PF), relative PF, allometrically scaled PF, rate of force development (RFD) (0 - 200 and 0 - 250 ms) and impulse (0 - 300 ms) were deemed reliable (ICC ≥ 0.86 and CV ≤ 9.4%) in the IMTP and ISqT based on predetermined criteria (ICC ≥ 0.8 and CV ≤ 10%). Impulse (0 - 200 ms and 0 - 250 ms) were reliable in the ISqT (ICC ≥ 0.92 and CV ≤ 9.9%). Participants produced significantly (p < 0.05) greater PF and impulse (0 - 300 ms) during the ISqT compared with the IMTP. When split by sex, female participants produced significantly ...
Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol in... more Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or m...
International Journal of Sports Physiology and Performance, 2021
Purpose: To investigate the relationships between internal and external training load (TL) metric... more Purpose: To investigate the relationships between internal and external training load (TL) metrics with elite international women’s basketball performance. Methods: Sessional ratings of perceived exertion, PlayerLoad™/minute, and training duration were collected from 13 elite international-level female basketball athletes (age 29.0 [3.7] y, stature 186.0 [9.8] cm, body mass 77.9 [11.6] kg) during the 18 weeks prior to the International Basketball Federation Olympic qualifying event for the 2016 Rio Olympic Games. Training stress balance, differential load, and the training efficiency index were calculated with 3 different smoothing methods. These TL metrics and their change in the last 21 days prior to competition were examined for their relationship to competition performance as coach ratings of performance. Results: For a number of TL variables, there were consistent significant small to moderate correlations with performance and significant small to large differences between succ...
Mixed martial arts (MMA) is a combat sport underpinned by techniques from other combat discipline... more Mixed martial arts (MMA) is a combat sport underpinned by techniques from other combat disciplines, in addition to strategies unique to the sport itself. These sports can be divided into two distinct categories (grappling or striking) based on differing technical demands. Uniquely, MMA combines both methods of combat and therefore appears to be physiologically complex requiring a spectrum of mechanical and metabolic qualities to drive performance. However, little is known about the physiological characteristics that distinguish higher- from lower-level MMA athletes. Such information provides guidance for training interventions, performance testing and talent identification. Furthermore, while MMA incorporates techniques from both grappling and striking sports, it is unknown precisely how these disciplines differ physiologically. Understanding the relationship between higher-level competitors in grappling and striking combat sports can provide further insight into the development of ...
Applied Physiology, Nutrition, and Metabolism, 2016
The purpose of this study was to examine the relationships between maximal voluntary postactivati... more The purpose of this study was to examine the relationships between maximal voluntary postactivation potentiation (PAP) and maximal knee extensor torque, quadriceps cross-sectional area (CSA) and volume, and type II myosin heavy chain (MHC) isoform percentage in human skeletal muscle. Thirteen resistance-trained men completed a test protocol consisting of 2 isokinetic knee extensions at 180°·s–1performed before and 1, 4, 7, and 10 min after the completion of 4 maximal knee extensions at 60°·s–1(i.e., a conditioning activity (CA)). Magnetic resonance imaging and muscle microbiopsy procedures were completed on separate days to assess quadriceps CSA and volume and MHC isoform content. Maximal voluntary PAP response was assessed as the ratio of the highest knee extensor torques measured before and after the CA. There were large to very large correlations between maximal voluntary PAP response and maximal knee extensor torque (r = 0.62) and quadriceps CSA (r = 0.68) and volume (r = 0.63)....
SUMMARY THIS RESEARCH BRIEF COVERS CONCURRENT STRENGTH AND ENDURANCE TRAINING IN ELITE SOCCER PLA... more SUMMARY THIS RESEARCH BRIEF COVERS CONCURRENT STRENGTH AND ENDURANCE TRAINING IN ELITE SOCCER PLAYERS, THE EFFECT OF HYPERTROPHY TRAINING PROTOCOLS WITH MAXIMAL LOADING ON NEURAL DRIVE, THE EFFECT OF CLUSTER SETS ON POWER IN JUMP SQUATS, AND THE EFFECT OF AGE ON REPEATED-SPRINT ABILITY IN YOUTH SOCCER PLAYERS.
International Journal of Sports Physiology and Performance, 2018
Purpose: To examine the reliability of peak velocity (PV), mean propulsive velocity (MPV), and me... more Purpose: To examine the reliability of peak velocity (PV), mean propulsive velocity (MPV), and mean velocity (MV) in the development of load–velocity profiles (LVP) in the full-depth free-weight back squat performed with maximal concentric effort. Methods: Eighteen resistance-trained men performed a baseline 1-repetition maximum (1-RM) back-squat trial and 3 subsequent 1-RM trials used for reliability analyses, with 48-h intervals between trials. 1-RM trials comprised lifts from 6 relative loads including 20%, 40%, 60%, 80%, 90%, and 100% 1-RM. Individualized LVPs for PV, MPV, or MV were derived from loads that were highly reliable based on the following criteria: intraclass correlation coefficient (ICC) >.70, coefficient of variation (CV) ≤10%, and Cohen d effect size (ES) <0.60. Results: PV was highly reliable at all 6 loads. MPV and MV were highly reliable at 20%, 40%, 60%, 80%, and 90% but not 100% 1-RM (MPV: ICC = .66, CV = 18.0%, ES = 0.10, SEM = 0.04 m·s−1; MV: ICC = .5...
The primary objective of this investigation was to investigate the relationships between training... more The primary objective of this investigation was to investigate the relationships between training load (TL), heart rate variability (HRV) and direct current potential (DC) with elite long jump performance prior to and during the 2016 Olympics Games. Sessional ratings of perceived exertion (sRPE), training duration, HRV and DC were collected from four elite athletes (26.4 ± 1.4 years, height 1.83 ± 0.05 m, weight 68.9 ± 5.0 kg) for a 16-week period in qualification for and competition at the 2016 Olympic Games. Acute and chronic TL, training stress balance and differential load were calculated with three different smoothing methods. These TL measures along with HRV and DC were examined for their relationship to intra-athlete performance using repeated measure correlations and linear mixed models. Successful compared to unsuccessful intra-athlete performances were characterised by a higher chronic TL (p < 0.01, f2 = 0.31) but only when TL was exponentially smoothed. There were also...
Introduction: Conceptually, it is important to understand the underlying physiological mechanisms... more Introduction: Conceptually, it is important to understand the underlying physiological mechanisms of any training program model. This understanding aids the coach/sport scientist in making better choices in manipulating variables in formulating the training model. These underlying mechanisms can be associated with training variable manipulation, fatigue management aspects and the overall health of the athlete. Hormone and cytokine concentrations can be linked to alterations resulting from the manipulation of training variables and to subsequent alterations in performance. For example, alterations in the testosterone: cortisol ratio (T:C) has been associated with alterations in training volume as well as physiological aspects such as lean body mass, fat content and strength/power performance. Although cytokine production is part of the adaptive process, markedly increased/excessive cytokine production has been related poor fatigue management and over training. Purpose: The purpose of this study was to investigate the alterations and relationships among training variables, and physiological variables. Subjects: Nine (9) D-1 collegiate throwers and 4 control subjects participated in the study. Methods: The throwers participated in an 11- week periodized resistance training and throws program. Volume load was recorded throughout the study. Hormone (testosterone and cortisol (C), and adipokine (adiponectin, leptin, and resistin) measurements were taken at weeks 1, 7, and 11 for the throwers. Results: Hormone values did not exhibit statistically significant changes across time; however, there were trends across time for C, the T:C ratio and adiponectin. Conclusions: Based on the hormonal and adipokine data, it appears that the training program produced some positive effects. These effects indicate a reasonable degree of fatigue management in that C decreased and the T:C ratio was increased as volume load decreased. Literature supports the idea that increases in adiponectin may be a positive outcome of a sound training protocol (Smith et al., 2000). The present observation indicates that adiponectin increased in concert with decreases in C and increases in the T:C. ratio. Considering the effects of these hormones and cytokines, these alterations over time indicate a lesser degree of obesity related inflammation and a higher degree of “fitness” and preparednes
The purpose of this investigation was to determine the acute effects of back squats on countermov... more The purpose of this investigation was to determine the acute effects of back squats on countermovement jump performance across multiple sets using a strength-power potentiation complex training protocol. Fifteen elite volleyball players performed three unloaded countermovement jumps (CMJ) following three repetitions of the back squat performed at either 65% or 87% of 1-RM, respectively, repeated for 10 sets. A control session of three CMJs was also repeated for 10 sets. Mean jump height performance was enhanced compared to performing CMJs only irrespective of which intensity was used (65% 1-RM: +3.3 ± 2.2% [CI: 1.0 to 5.6]; 87% 1-RM: 2.6 ± 1.9% [CI: 0.7 to 4.5]). Subjects with a greater relative strength possessed a very likely large (97%; ES = 1.51) chance of improvement in jump height across 10 sets of the protocol prescribed using the intensity of 87% 1-RM and a likely moderate (89%; ES = 0.94) and very likely large (97%; ES = 1.76) chance of improvement in maximum concentric imp...
Journal of Functional Morphology and Kinesiology, 2019
The purpose of this review was to provide a physiological rationale for the use of eccentric resi... more The purpose of this review was to provide a physiological rationale for the use of eccentric resistance training and to provide an overview of the most commonly prescribed eccentric training methods. Based on the existing literature, there is a strong physiological rationale for the incorporation of eccentric training into a training program for an individual seeking to maximize muscle size, strength, and power. Specific adaptations may include an increase in muscle cross-sectional area, force output, and fiber shortening velocities, all of which have the potential to benefit power production characteristics. Tempo eccentric training, flywheel inertial training, accentuated eccentric loading, and plyometric training are commonly implemented in applied contexts. These methods tend to involve different force absorption characteristics and thus, overload the muscle or musculotendinous unit in different ways during lengthening actions. For this reason, they may produce different magnitu...
Journal of strength and conditioning research, 2018
Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and bet... more Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and between-session reliability of the isometric midthigh pull in young female athletes. J Strength Cond Res 32(7): 1892-1901, 2018-To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre- and post-peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation ...
International journal of sports medicine, Jan 21, 2018
The aim of this study was to compare three specific concentric and eccentric muscle action traini... more The aim of this study was to compare three specific concentric and eccentric muscle action training protocols on quadriceps-hamstrings neuromuscular adaptations. Forty male volunteers performed 6 weeks of training (two sessions/week) of their dominant and non-dominant legs on an isokinetic dynamometer. They were randomly assigned to one of four groups; concentric quadriceps and concentric hamstrings (CON/CON, n=10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n=10), concentric quadriceps and eccentric hamstrings (CON/ECC, n=10), or no training (CTRL, n=10). Intensity of training was increased every week by decreasing the angular velocity for concentric and increasing it for eccentric groups in 30°/s increments. Volume of training was increased by adding one set every week. Dominant leg quadriceps and hamstrings muscle thickness, muscle quality, muscle activation, muscle coactivation, and electromechanical delay were tested before and after training. Results revealed that...
International journal of sports physiology and performance, Jan 28, 2017
This investigation examined the reliability and usefulness of the isometric mid-thigh pull (IMTP)... more This investigation examined the reliability and usefulness of the isometric mid-thigh pull (IMTP) and isometric squat (ISqT) performed at the same knee and hip angles. The scores produced in each test were compared to determine the magnitude of differences between tests. Twenty six male and female athletes (23.6±4.3 y; 1.75±0.07 m; 68.8±9.7 kg) performed 2 maximal repetitions of the IMTP and ISqT following a specific warm up. Maximum force, absolute peak force (PF), relative PF, allometrically scaled PF, rate of force development (RFD) (0 - 200 and 0 - 250 ms) and impulse (0 - 300 ms) were deemed reliable (ICC ≥ 0.86 and CV ≤ 9.4%) in the IMTP and ISqT based on predetermined criteria (ICC ≥ 0.8 and CV ≤ 10%). Impulse (0 - 200 ms and 0 - 250 ms) were reliable in the ISqT (ICC ≥ 0.92 and CV ≤ 9.9%). Participants produced significantly (p < 0.05) greater PF and impulse (0 - 300 ms) during the ISqT compared with the IMTP. When split by sex, female participants produced significantly ...
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Papers by Greg Haff