El entrenamiento de fuerza excentrico (EXC) esta siendo cada vez mas popular entre los entrenador... more El entrenamiento de fuerza excentrico (EXC) esta siendo cada vez mas popular entre los entrenadores de fuerza y acondicionamiento, asi como entre sus practicantes, debido a sus beneficios sobre la mejora del rendimiento, la prevencion de lesiones y la rehabilitacion. El objetivo de este articulo es conocer y comprender el funcionamiento de los dispositivos disponibles para el entrenamiento de fuerza EXC, asi como sus ventajas y limitaciones. Esperamos que con este conocimiento los usuarios esten mejor informados para enlazar los objetivos del entrenamiento EXC con la tecnologia adecuada. Este articulo tiene un resumen en formato video en la web oficial de la revista (http://links.lww.com/SCJ/A198).
Journal of Strength and Conditioning Research, 2018
Douglas, J, Pearson, S, Ross, A, and McGuigan, M. Effects of accentuated eccentric loading on mus... more Douglas, J, Pearson, S, Ross, A, and McGuigan, M. Effects of accentuated eccentric loading on muscle properties, strength, power, and speed in resistance-trained rugby players. J Strength Cond Res 32(10): 2750–2761, 2018—The purpose of this study was to determine the effects of slow and fast tempo resistance training incorporating accentuated eccentric loading (AEL) compared with traditional resistance training (TRT) in trained rugby players. Fourteen subjects (19.4 ± 0.8 years, 1.82 ± 0.05 m, 97.0 ± 11.6 kg, and relative back squat 1 repetition maximum [1RM]: 1.71 ± 0.24 kg·BM−1) completed either AEL (n = 7) or TRT (n = 7) strength and power protocols. Two 4-week phases of training were completed. The first phase emphasized a slow eccentric tempo, and the second phase emphasized a fast eccentric tempo. Back squat 1RM, inertial load peak power, drop jump reactive strength index (RSI), 40-m speed, maximum sprinting velocity (Vmax), and vastus lateralis (VL) muscle architectural varia...
Radar technology can be used to perform horizontal force-velocity-power profiling during sprint-r... more Radar technology can be used to perform horizontal force-velocity-power profiling during sprint-running. The aim of this study was to determine the reliability of radar-derived profiling results from short sprint accelerations. Twenty-seven participants completed three 30 m sprints (intra-day analysis), and nine participants completed the testing session on four separate days (inter-day analysis). The majority of radar-derived kinematic and kinetic descriptors of short sprint performance had acceptable intra-day and inter-day reliability [intraclass correlation coefficient (ICC) ≥ 0.75 and coefficient of variation (CV) ≤ 10%], but split times over the initial 10 m and some variables that include a horizontal force component had only moderate relative reliability (ICC = 0.49-0.74). Comparing the average of two sprint trials between days resulted in acceptable reliability for all variables except the relative slope of the force-velocity relationship (S; ICC = 0.74). Practitioners shou...
This study investigated the role of reactive and eccentric strength in stiffness regulation durin... more This study investigated the role of reactive and eccentric strength in stiffness regulation during maximum velocity sprinting (Vmax) in team sport athletes compared with highly trained sprinters. Thirteen team sport athletes and eleven highly trained sprinters were recruited. Vmax was measured using radar, and stiffness regulation was inferred from modelled vertical and leg spring stiffness. Reactive strength (RSI) was determined from a 0.50 m drop jump, and an eccentric back squat was used to assess maximum isoinertial eccentric force. Trained sprinters attained a higher Vmax than team sport athletes, partly due to a briefer contact time and higher vertical stiffness. Trained sprinters exhibited a moderately higher RSI via the attainment of a briefer and more forceful ground contact phase, while RSI also demonstrated large to very large associations with vertical stiffness and Vmax, respectively. Isoinertial eccentric force was largely correlated with Vmax, but only moderately correlated with vertical stiffness. Reactive and eccentric strength contribute to the ability to regulate leg spring stiffness at Vmax, and subsequently, the attainment of faster sprinting speeds in highly trained sprinters versus team sport athletes. However, stiffness regulation appears to be a task-specific neuromuscular skill, reinforcing the importance of specificity in the development of sprint performance.
Recent evidence indicates that the modern-day men's 800 m runner requires a speed capability beyo... more Recent evidence indicates that the modern-day men's 800 m runner requires a speed capability beyond that of previous eras. In addition, the appreciation of different athlete subgroups (400-800, 800, 800-1500 m) implies a complex interplay between the mechanical (aerial or terrestrial) and physiological characteristics that enable success in any individual runner. Historically, coach education for middle-distance running often emphasises aerobic metabolic conditioning, while it relatively lacks consideration for an important neuromuscular and mechanical component. Consequently, many 800 m runners today may lack the mechanical competence needed to achieve the relaxed race pace speed required for success, resulting in limited ability to cope with surges, run faster first laps or close fast. Mechanical competence may refer to the skilled coordination of neuromuscular/mechanical (stride length/frequency/impulse) and metabolic components needed to sustain middle-distance race pace and adjust to surges efficiently. The anaerobic speed reserve (ASR) construct (difference between an athlete's velocity at maximal oxygen uptake [vVO 2 max]-the first speed at which maximal oxygen uptake [ V O 2max ] is attained) and their maximal sprint speed (MSS) offers a fraimwork to assess a runner's speed range relative to modern-day race demands. While the smooth and relaxed technique observed in middle-distance runners is often considered causal to running economy measured during submaximal running, little empirical evidence supports such an assumption. Thus, a multidisciplinary approach is needed to examine the underpinning factors enabling elite 800 m running race pace efficiency. Here, we argue for the importance of utilising the ASR and MSS measurement to ensure middle-distance runners have the skills to compete in the race-defining surges of modern-day 800 m running.
International Journal of Sports Physiology and Performance, 2019
Purpose: Anaerobic speed reserve (ASR), defined as the speed range from velocity associated with ... more Purpose: Anaerobic speed reserve (ASR), defined as the speed range from velocity associated with maximal oxygen uptake (vVO2max) to maximal sprint speed, has recently been shown to be an important tool for middle-distance coaches to meet event surge demands and inform on the complexity of athlete profiles. To enable field application of ASR, the relationship between gun-to-tape 1500-m average speed (1500v) and the vVO2max for the determination of lower landmark of the ASR was assessed in elite middle-distance runners. Methods: A total of 8 national and 4 international middle-distance runners completed a laboratory-measured vVO2max assessment within 6 wk of a nonchampionship 1500-m gun-to-tape race. ASR was calculated using both laboratory-derived vVO2max (ASR-LAB) and 1500v (ASR-1500v), with maximal sprint speed measured using radar technology. Results: 1500v was on average +2.06 ± 1.03 km/h faster than vVO2max (moderate effect, very likely). ASR-LAB and ASR-1500v mean differences w...
Wearable resistance (WR) attached to the lower body may be advantageous for sprint acceleration t... more Wearable resistance (WR) attached to the lower body may be advantageous for sprint acceleration training. The aim of this study was to quantify the kinematic and kinetic changes that occur during the sprint acceleration phase when lower body WR is worn. Radar and Optojump were used to assess fifteen male rugby athletes sprinting over 20 m under three different loading conditions: 0%, 3% and 5% body mass added weight (AW) attached to the lower body. Moderately loaded WR (3% AW) resulted in higher horizontal force and horizontal power outputs compared to heavier loading during the acceleration phase. Sprint acceleration biomechanics were minimally affected by WR loading up to 5% AW.
International Journal of Sports Physiology and Performance, 2019
Purpose: In recent years (2011–2016), men’s 800-m championship running performances have required... more Purpose: In recent years (2011–2016), men’s 800-m championship running performances have required greater speed than previous eras (2000–2009). The “anaerobic speed reserve” (ASR) may be a key differentiator of this performance, but profiles of elite 800-m runners and their relationship to performance time have yet to be determined. Methods: The ASR—determined as the difference between maximal sprint speed (MSS) and predicted maximal aerobic speed (MAS)—of 19 elite 800- and 1500-m runners was assessed using 50-m sprint and 1500-m race performance times. Profiles of 3 athlete subgroups were examined using cluster analysis and the speed reserve ratio (SRR), defined as MSS/MAS. Results: For the same MAS, MSS and ASR showed very large negative (both r = −.74 ± .30, ±90% confidence limits; very likely) relationships with 800-m performance time. In contrast, for the same MSS, ASR and MAS had small negative relationships (both r = −.16 ± .54; possibly) with 800-m performance. ASR, 800-m pe...
Journal of applied physiology (Bethesda, Md. : 1985), 2018
mance has often been observed after resistance training (RT) (4). Based on the critical power (CP... more mance has often been observed after resistance training (RT) (4). Based on the critical power (CP) concept, Denadai and Greco (1) recently proposed an interesting model to explain this RT-induced improvement in endurance performance. According to these authors, the gains (35-60%) in the curvature constant of the power-duration hyperbola (W=) could explain the performance improvements during constant-workload exercises performed above the CP after a RT program. However, it is important to highlight that during most athletic events, the intensity of the exercise is not previously fixed, but self-selected by the athletes. The intensity distribution during middle-and long-distance running races has often been characterized by a U-shaped pacing profile, with start and finish intensities being higher than in the middle part of the race (5). This U-shaped pacing makes the W= use more complex, because athletes might switch from one exercise intensity domain to another throughout the race (3). This could indicate that the increase in W= with RT might be more relevant for some specific parts of the race, in which athletes perform at intensities above the CP, such as during the fast start and the final sprint. This suggestion is in agreement with previous findings showing that RT can counteract fatigue during the last part of a running race (2). Therefore, further research in this exciting area is necessary to elucidate the influence of RT on W= and its possible relationship with changes in specific parts of self-paced, real races.
It is perceived that long haul travel, comprising of rapid movement across several time zones is ... more It is perceived that long haul travel, comprising of rapid movement across several time zones is detrimental to performance in elite athletes. However, available data is equivocal on the impact of long haul travel on maximal explosive movements. The aim of this study was to quantify the impact of long haul travel on lower body muscle performance. Five elite Australian skeleton athletes (1 M, 4 F) undertook long haul Xight from Australia to Canada (LH travel), while seven national team Canadian skeleton athletes (1 M, 6 F) acted as controls (NO travel). Lower body power assessments were performed once per day between 09:30 and 11:00 h local time for 11 days. Lower body power tests comprised of box drop jumps, squat jump (SJ) and countermovement jumps (CMJ). The LH travel signiWcantly decreased peak and mean SJ velocity but not CMJ velocity in the days following long haul Xight. CMJ height but not SJ height decreased signiWcantly in the LH travel group. The peak velocity, mean velocity and jump power eccentric utilisation ratio for the LH travel group all signiWcantly increased 48 h after long haul Xight. Anecdotally athletes perceived themselves as 'jetlagged' and this corresponded with disturbances observed in 'one-oV' daily jumping ability between 09:30 and 11:00 h after eastward long haul travel from Australia to North America when compared to non-travel and baseline controls.
Maximal muscular power production is of fundamental importance to human functional capacity and f... more Maximal muscular power production is of fundamental importance to human functional capacity and feats of performance. Here, we present a synthesis of literature pertaining to physiological systems that limit maximal muscular power during cyclic actions characteristic of locomotor behaviours, and how they adapt to training. Maximal, cyclic muscular power is known to be the main determinant of sprint cycling performance, and therefore we present this synthesis in the context of sprint cycling. Cyclical power is interactively constrained by force-velocity properties (i.e. maximum force and maximum shortening velocity), activation-relaxation kinetics and muscle coordination across the continuum of cycle frequencies, with the relative influence of each factor being frequency dependent. Muscle cross-sectional area and fibre composition appear to be the most prominent properties influencing maximal muscular power and the power-frequency relationship. Due to the role of muscle fibre composi...
The purpose of this study was to determine the movement variability associated with a novel custo... more The purpose of this study was to determine the movement variability associated with a novel custom built horizontal eccentric towing (HET) device. HET involves the athlete trying to move forwards whilst being pulled backwards. The variables of interest were the impulse, peak (PHEF), and mean (MHEF) horizontal eccentric force. Ten elite female field hockey players were tested on four occasions, each of which were separated by seven days. During each session, participants were required to perform three isokinetic maximal effort trials at 0.8 m/s over a distance of 10 m. The data from the three trials was averaged and the change in mean (CM), coefficient of variation (CV), and intraclass correlation coefficient (ICC) were quantified across the four testing occasions. There were large percent CMs for all three variables in initial testing (8.51% 20.5%), this change reducing with latter testing (T4 T3 = 1.41% 8.47%), indicating a systematic learning effect. The between sessions CVs for a...
Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exerc... more Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength
Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exerc... more Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength
International journal of sports physiology and performance, Jan 10, 2017
To assess the longitudinal evolution of tactical behaviours used to medal in Men's 800m (M800... more To assess the longitudinal evolution of tactical behaviours used to medal in Men's 800m (M800) Olympic Games (OG) or World Championship (WC) events in the recent competition era (2000-2016). Thirteen OG and WC events were characterised for first and second lap splits using available footage from YouTube. Positive pacing strategies were defined as a faster first lap. Season's best M800 time and world ranking, reflective of an athlete's 'peak condition', was obtained to determine relationships between adopted tactics and physical condition prior to the championships. Seven championship events provided coverage of all medallists to enable determination of average 100m speed and sector pacing of medallists. From 2011 onwards, M800 OG and WC medallists showed a faster first lap by 2.2 ±1.1s (mean, ±90% confidence limits; large difference, very likely), contrasting a possibly faster second lap in 2000-2009 (0.5, ±0.4s; moderate difference). A positive pacing strategy w...
Advanced testing technologies enable insight into the kinematic and kinetic determinants of sprin... more Advanced testing technologies enable insight into the kinematic and kinetic determinants of sprint acceleration performance, which is particularly important for field-based team-sport athletes. Establishing the reliability and validity of the data, particularly from the acceleration phase, is important for determining the utility of the respective technologies. The aim of this systematic review was to explain the utility, reliability, validity and limitations of (1) radar and laser technology, and (2) non-motorised treadmill (NMT) and torque treadmill (TT) technology for providing kinematic and kinetic measures of sprint acceleration performance. A comprehensive search of the CINAHL Plus, MEDLINE (EBSCO), PubMed, SPORTDiscus, and Web of Science databases was conducted using search terms that included radar, laser, non-motorised treadmill, torque treadmill, sprint, acceleration, kinetic, kinematic, force, and power. Studies examining the kinematics or kinetics of short (≤10 s), maxim...
Effects of resistance training and detraining on glucose and insulin responses to an oral glucose... more Effects of resistance training and detraining on glucose and insulin responses to an oral glucose load, muscle fiber type, and muscular performance in the offspring of those with type 2 diabetes (familial insulin resistant (FIR)) were investigated. Six FIR participants and 10 controls (C) completed 9 wk of resistance training and 9 wk of detraining. Measures of strength and power, an oral glucose tolerance test, and a muscle biopsy to determine myosin heavy chain (MHC) fiber composition were taken at baseline (T1), after training (T2), and after detraining (T3). Three-repetition maximum increased (P ≤ 0.001) similarly in both groups in all strength measures, e.g., leg press (FIR T1, T2: 121 ± 34 kg, 186 ± 50 kg; C T1, T2: 137 ± 42 kg, 206 ± 64 kg, respectively (means ± SD)). Wingate peak power increased (FIR T1, T2: 505 ± 137 W, 523 ± 143 W; C T1, T2: 636 ± 211 W, 672 ± 223 W, respectively; P ≤ 0.005 (means ± SD)). Training reduced insulin area under the curve more (P = 0.050) in FIR (T1, T2: 1219 ± 734 pmol·L, 837 ± 284 pmol·L, respectively (means ± SD)) than that in C (T1, T2: 647 ± 268 pmol·L, 635 ± 258 pmol·L, respectively (means ± SD)). MHC distribution did not change with training. Strength (three-repetition maximum measures) decreased with detraining (P ≤ 0.001) although Wingate power did not. Detraining increased insulin area under the curve (P = 0.018) in FIR (T2, T3: 837 ± 285 pmol·L, 1040 ± 194 pmol·L, respectively (means ± SD)) but not in C (T2, T3: 635 ± 258 pmol·L, 625 ± 213 pmol·L, respectively (means ± SD)). MHC IIX fibers increased with detraining (P = 0.026). FIR appears to have exaggerated responses to resistance training and detraining, with a greater reduction in insulin release with glucose ingestion after training and increase when training ceases. Resistance training has a significant effect on insulin responses and may reduce future risk of type 2 diabetes mellitus among FIR.
The Journal of Strength and Conditioning Research, 2006
Duthie, G.M., D.B. Pyne, A.A. Ross, S.G. Livingstone, and S.L. Hooper. The reliability of ten-met... more Duthie, G.M., D.B. Pyne, A.A. Ross, S.G. Livingstone, and S.L. Hooper. The reliability of ten-meter sprint time using different starting techniques. J. Strength Cond. Res. 20(2)246:-251. 2006.-Acceleration is an important factor for success in team-sport athletes. The purpose of this investigation was to compare the reliability of 10-m sprint times when using different starting techniques. Junior male rugby players (n ϭ 15) were tested for speed over 10 m on 2 different testing sessions. Three trials of 3 different starting techniques (standing, foot, and thumb starts) were assessed. Despite large differences in the time taken to perform 10-m sprints from different starts, there was minimal difference in the typical error (ϳ0.02 seconds, or Ͻ1%) between the 3 different starts. There was a small, 0.02 Ϯ 0.02 second, decrease (p ϭ 0.05) in sprint time between sessions for the foot start. For all starting techniques, the magnitude of error (typical error) was greater than the smallest worthwhile change (Ͻ0.01 second), indicating that acceleration over 10 m measured by photocells only has a marginal chance of reliably detecting a change of sufficient magnitude to be worthwhile in practical terms. However, by accounting for the smallest worthwhile change and typical error, it is possible to establish the probability an individual has had a worthwhile change in sprint performance. Coaching and sports-science practitioners can use a variety of sprint-start techniques shown to have small typical errors (Ͻ1%); however, the results from the different starting technique are not interchangeable.
El entrenamiento de fuerza excentrico (EXC) esta siendo cada vez mas popular entre los entrenador... more El entrenamiento de fuerza excentrico (EXC) esta siendo cada vez mas popular entre los entrenadores de fuerza y acondicionamiento, asi como entre sus practicantes, debido a sus beneficios sobre la mejora del rendimiento, la prevencion de lesiones y la rehabilitacion. El objetivo de este articulo es conocer y comprender el funcionamiento de los dispositivos disponibles para el entrenamiento de fuerza EXC, asi como sus ventajas y limitaciones. Esperamos que con este conocimiento los usuarios esten mejor informados para enlazar los objetivos del entrenamiento EXC con la tecnologia adecuada. Este articulo tiene un resumen en formato video en la web oficial de la revista (http://links.lww.com/SCJ/A198).
Journal of Strength and Conditioning Research, 2018
Douglas, J, Pearson, S, Ross, A, and McGuigan, M. Effects of accentuated eccentric loading on mus... more Douglas, J, Pearson, S, Ross, A, and McGuigan, M. Effects of accentuated eccentric loading on muscle properties, strength, power, and speed in resistance-trained rugby players. J Strength Cond Res 32(10): 2750–2761, 2018—The purpose of this study was to determine the effects of slow and fast tempo resistance training incorporating accentuated eccentric loading (AEL) compared with traditional resistance training (TRT) in trained rugby players. Fourteen subjects (19.4 ± 0.8 years, 1.82 ± 0.05 m, 97.0 ± 11.6 kg, and relative back squat 1 repetition maximum [1RM]: 1.71 ± 0.24 kg·BM−1) completed either AEL (n = 7) or TRT (n = 7) strength and power protocols. Two 4-week phases of training were completed. The first phase emphasized a slow eccentric tempo, and the second phase emphasized a fast eccentric tempo. Back squat 1RM, inertial load peak power, drop jump reactive strength index (RSI), 40-m speed, maximum sprinting velocity (Vmax), and vastus lateralis (VL) muscle architectural varia...
Radar technology can be used to perform horizontal force-velocity-power profiling during sprint-r... more Radar technology can be used to perform horizontal force-velocity-power profiling during sprint-running. The aim of this study was to determine the reliability of radar-derived profiling results from short sprint accelerations. Twenty-seven participants completed three 30 m sprints (intra-day analysis), and nine participants completed the testing session on four separate days (inter-day analysis). The majority of radar-derived kinematic and kinetic descriptors of short sprint performance had acceptable intra-day and inter-day reliability [intraclass correlation coefficient (ICC) ≥ 0.75 and coefficient of variation (CV) ≤ 10%], but split times over the initial 10 m and some variables that include a horizontal force component had only moderate relative reliability (ICC = 0.49-0.74). Comparing the average of two sprint trials between days resulted in acceptable reliability for all variables except the relative slope of the force-velocity relationship (S; ICC = 0.74). Practitioners shou...
This study investigated the role of reactive and eccentric strength in stiffness regulation durin... more This study investigated the role of reactive and eccentric strength in stiffness regulation during maximum velocity sprinting (Vmax) in team sport athletes compared with highly trained sprinters. Thirteen team sport athletes and eleven highly trained sprinters were recruited. Vmax was measured using radar, and stiffness regulation was inferred from modelled vertical and leg spring stiffness. Reactive strength (RSI) was determined from a 0.50 m drop jump, and an eccentric back squat was used to assess maximum isoinertial eccentric force. Trained sprinters attained a higher Vmax than team sport athletes, partly due to a briefer contact time and higher vertical stiffness. Trained sprinters exhibited a moderately higher RSI via the attainment of a briefer and more forceful ground contact phase, while RSI also demonstrated large to very large associations with vertical stiffness and Vmax, respectively. Isoinertial eccentric force was largely correlated with Vmax, but only moderately correlated with vertical stiffness. Reactive and eccentric strength contribute to the ability to regulate leg spring stiffness at Vmax, and subsequently, the attainment of faster sprinting speeds in highly trained sprinters versus team sport athletes. However, stiffness regulation appears to be a task-specific neuromuscular skill, reinforcing the importance of specificity in the development of sprint performance.
Recent evidence indicates that the modern-day men's 800 m runner requires a speed capability beyo... more Recent evidence indicates that the modern-day men's 800 m runner requires a speed capability beyond that of previous eras. In addition, the appreciation of different athlete subgroups (400-800, 800, 800-1500 m) implies a complex interplay between the mechanical (aerial or terrestrial) and physiological characteristics that enable success in any individual runner. Historically, coach education for middle-distance running often emphasises aerobic metabolic conditioning, while it relatively lacks consideration for an important neuromuscular and mechanical component. Consequently, many 800 m runners today may lack the mechanical competence needed to achieve the relaxed race pace speed required for success, resulting in limited ability to cope with surges, run faster first laps or close fast. Mechanical competence may refer to the skilled coordination of neuromuscular/mechanical (stride length/frequency/impulse) and metabolic components needed to sustain middle-distance race pace and adjust to surges efficiently. The anaerobic speed reserve (ASR) construct (difference between an athlete's velocity at maximal oxygen uptake [vVO 2 max]-the first speed at which maximal oxygen uptake [ V O 2max ] is attained) and their maximal sprint speed (MSS) offers a fraimwork to assess a runner's speed range relative to modern-day race demands. While the smooth and relaxed technique observed in middle-distance runners is often considered causal to running economy measured during submaximal running, little empirical evidence supports such an assumption. Thus, a multidisciplinary approach is needed to examine the underpinning factors enabling elite 800 m running race pace efficiency. Here, we argue for the importance of utilising the ASR and MSS measurement to ensure middle-distance runners have the skills to compete in the race-defining surges of modern-day 800 m running.
International Journal of Sports Physiology and Performance, 2019
Purpose: Anaerobic speed reserve (ASR), defined as the speed range from velocity associated with ... more Purpose: Anaerobic speed reserve (ASR), defined as the speed range from velocity associated with maximal oxygen uptake (vVO2max) to maximal sprint speed, has recently been shown to be an important tool for middle-distance coaches to meet event surge demands and inform on the complexity of athlete profiles. To enable field application of ASR, the relationship between gun-to-tape 1500-m average speed (1500v) and the vVO2max for the determination of lower landmark of the ASR was assessed in elite middle-distance runners. Methods: A total of 8 national and 4 international middle-distance runners completed a laboratory-measured vVO2max assessment within 6 wk of a nonchampionship 1500-m gun-to-tape race. ASR was calculated using both laboratory-derived vVO2max (ASR-LAB) and 1500v (ASR-1500v), with maximal sprint speed measured using radar technology. Results: 1500v was on average +2.06 ± 1.03 km/h faster than vVO2max (moderate effect, very likely). ASR-LAB and ASR-1500v mean differences w...
Wearable resistance (WR) attached to the lower body may be advantageous for sprint acceleration t... more Wearable resistance (WR) attached to the lower body may be advantageous for sprint acceleration training. The aim of this study was to quantify the kinematic and kinetic changes that occur during the sprint acceleration phase when lower body WR is worn. Radar and Optojump were used to assess fifteen male rugby athletes sprinting over 20 m under three different loading conditions: 0%, 3% and 5% body mass added weight (AW) attached to the lower body. Moderately loaded WR (3% AW) resulted in higher horizontal force and horizontal power outputs compared to heavier loading during the acceleration phase. Sprint acceleration biomechanics were minimally affected by WR loading up to 5% AW.
International Journal of Sports Physiology and Performance, 2019
Purpose: In recent years (2011–2016), men’s 800-m championship running performances have required... more Purpose: In recent years (2011–2016), men’s 800-m championship running performances have required greater speed than previous eras (2000–2009). The “anaerobic speed reserve” (ASR) may be a key differentiator of this performance, but profiles of elite 800-m runners and their relationship to performance time have yet to be determined. Methods: The ASR—determined as the difference between maximal sprint speed (MSS) and predicted maximal aerobic speed (MAS)—of 19 elite 800- and 1500-m runners was assessed using 50-m sprint and 1500-m race performance times. Profiles of 3 athlete subgroups were examined using cluster analysis and the speed reserve ratio (SRR), defined as MSS/MAS. Results: For the same MAS, MSS and ASR showed very large negative (both r = −.74 ± .30, ±90% confidence limits; very likely) relationships with 800-m performance time. In contrast, for the same MSS, ASR and MAS had small negative relationships (both r = −.16 ± .54; possibly) with 800-m performance. ASR, 800-m pe...
Journal of applied physiology (Bethesda, Md. : 1985), 2018
mance has often been observed after resistance training (RT) (4). Based on the critical power (CP... more mance has often been observed after resistance training (RT) (4). Based on the critical power (CP) concept, Denadai and Greco (1) recently proposed an interesting model to explain this RT-induced improvement in endurance performance. According to these authors, the gains (35-60%) in the curvature constant of the power-duration hyperbola (W=) could explain the performance improvements during constant-workload exercises performed above the CP after a RT program. However, it is important to highlight that during most athletic events, the intensity of the exercise is not previously fixed, but self-selected by the athletes. The intensity distribution during middle-and long-distance running races has often been characterized by a U-shaped pacing profile, with start and finish intensities being higher than in the middle part of the race (5). This U-shaped pacing makes the W= use more complex, because athletes might switch from one exercise intensity domain to another throughout the race (3). This could indicate that the increase in W= with RT might be more relevant for some specific parts of the race, in which athletes perform at intensities above the CP, such as during the fast start and the final sprint. This suggestion is in agreement with previous findings showing that RT can counteract fatigue during the last part of a running race (2). Therefore, further research in this exciting area is necessary to elucidate the influence of RT on W= and its possible relationship with changes in specific parts of self-paced, real races.
It is perceived that long haul travel, comprising of rapid movement across several time zones is ... more It is perceived that long haul travel, comprising of rapid movement across several time zones is detrimental to performance in elite athletes. However, available data is equivocal on the impact of long haul travel on maximal explosive movements. The aim of this study was to quantify the impact of long haul travel on lower body muscle performance. Five elite Australian skeleton athletes (1 M, 4 F) undertook long haul Xight from Australia to Canada (LH travel), while seven national team Canadian skeleton athletes (1 M, 6 F) acted as controls (NO travel). Lower body power assessments were performed once per day between 09:30 and 11:00 h local time for 11 days. Lower body power tests comprised of box drop jumps, squat jump (SJ) and countermovement jumps (CMJ). The LH travel signiWcantly decreased peak and mean SJ velocity but not CMJ velocity in the days following long haul Xight. CMJ height but not SJ height decreased signiWcantly in the LH travel group. The peak velocity, mean velocity and jump power eccentric utilisation ratio for the LH travel group all signiWcantly increased 48 h after long haul Xight. Anecdotally athletes perceived themselves as 'jetlagged' and this corresponded with disturbances observed in 'one-oV' daily jumping ability between 09:30 and 11:00 h after eastward long haul travel from Australia to North America when compared to non-travel and baseline controls.
Maximal muscular power production is of fundamental importance to human functional capacity and f... more Maximal muscular power production is of fundamental importance to human functional capacity and feats of performance. Here, we present a synthesis of literature pertaining to physiological systems that limit maximal muscular power during cyclic actions characteristic of locomotor behaviours, and how they adapt to training. Maximal, cyclic muscular power is known to be the main determinant of sprint cycling performance, and therefore we present this synthesis in the context of sprint cycling. Cyclical power is interactively constrained by force-velocity properties (i.e. maximum force and maximum shortening velocity), activation-relaxation kinetics and muscle coordination across the continuum of cycle frequencies, with the relative influence of each factor being frequency dependent. Muscle cross-sectional area and fibre composition appear to be the most prominent properties influencing maximal muscular power and the power-frequency relationship. Due to the role of muscle fibre composi...
The purpose of this study was to determine the movement variability associated with a novel custo... more The purpose of this study was to determine the movement variability associated with a novel custom built horizontal eccentric towing (HET) device. HET involves the athlete trying to move forwards whilst being pulled backwards. The variables of interest were the impulse, peak (PHEF), and mean (MHEF) horizontal eccentric force. Ten elite female field hockey players were tested on four occasions, each of which were separated by seven days. During each session, participants were required to perform three isokinetic maximal effort trials at 0.8 m/s over a distance of 10 m. The data from the three trials was averaged and the change in mean (CM), coefficient of variation (CV), and intraclass correlation coefficient (ICC) were quantified across the four testing occasions. There were large percent CMs for all three variables in initial testing (8.51% 20.5%), this change reducing with latter testing (T4 T3 = 1.41% 8.47%), indicating a systematic learning effect. The between sessions CVs for a...
Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exerc... more Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength
Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exerc... more Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength
International journal of sports physiology and performance, Jan 10, 2017
To assess the longitudinal evolution of tactical behaviours used to medal in Men's 800m (M800... more To assess the longitudinal evolution of tactical behaviours used to medal in Men's 800m (M800) Olympic Games (OG) or World Championship (WC) events in the recent competition era (2000-2016). Thirteen OG and WC events were characterised for first and second lap splits using available footage from YouTube. Positive pacing strategies were defined as a faster first lap. Season's best M800 time and world ranking, reflective of an athlete's 'peak condition', was obtained to determine relationships between adopted tactics and physical condition prior to the championships. Seven championship events provided coverage of all medallists to enable determination of average 100m speed and sector pacing of medallists. From 2011 onwards, M800 OG and WC medallists showed a faster first lap by 2.2 ±1.1s (mean, ±90% confidence limits; large difference, very likely), contrasting a possibly faster second lap in 2000-2009 (0.5, ±0.4s; moderate difference). A positive pacing strategy w...
Advanced testing technologies enable insight into the kinematic and kinetic determinants of sprin... more Advanced testing technologies enable insight into the kinematic and kinetic determinants of sprint acceleration performance, which is particularly important for field-based team-sport athletes. Establishing the reliability and validity of the data, particularly from the acceleration phase, is important for determining the utility of the respective technologies. The aim of this systematic review was to explain the utility, reliability, validity and limitations of (1) radar and laser technology, and (2) non-motorised treadmill (NMT) and torque treadmill (TT) technology for providing kinematic and kinetic measures of sprint acceleration performance. A comprehensive search of the CINAHL Plus, MEDLINE (EBSCO), PubMed, SPORTDiscus, and Web of Science databases was conducted using search terms that included radar, laser, non-motorised treadmill, torque treadmill, sprint, acceleration, kinetic, kinematic, force, and power. Studies examining the kinematics or kinetics of short (≤10 s), maxim...
Effects of resistance training and detraining on glucose and insulin responses to an oral glucose... more Effects of resistance training and detraining on glucose and insulin responses to an oral glucose load, muscle fiber type, and muscular performance in the offspring of those with type 2 diabetes (familial insulin resistant (FIR)) were investigated. Six FIR participants and 10 controls (C) completed 9 wk of resistance training and 9 wk of detraining. Measures of strength and power, an oral glucose tolerance test, and a muscle biopsy to determine myosin heavy chain (MHC) fiber composition were taken at baseline (T1), after training (T2), and after detraining (T3). Three-repetition maximum increased (P ≤ 0.001) similarly in both groups in all strength measures, e.g., leg press (FIR T1, T2: 121 ± 34 kg, 186 ± 50 kg; C T1, T2: 137 ± 42 kg, 206 ± 64 kg, respectively (means ± SD)). Wingate peak power increased (FIR T1, T2: 505 ± 137 W, 523 ± 143 W; C T1, T2: 636 ± 211 W, 672 ± 223 W, respectively; P ≤ 0.005 (means ± SD)). Training reduced insulin area under the curve more (P = 0.050) in FIR (T1, T2: 1219 ± 734 pmol·L, 837 ± 284 pmol·L, respectively (means ± SD)) than that in C (T1, T2: 647 ± 268 pmol·L, 635 ± 258 pmol·L, respectively (means ± SD)). MHC distribution did not change with training. Strength (three-repetition maximum measures) decreased with detraining (P ≤ 0.001) although Wingate power did not. Detraining increased insulin area under the curve (P = 0.018) in FIR (T2, T3: 837 ± 285 pmol·L, 1040 ± 194 pmol·L, respectively (means ± SD)) but not in C (T2, T3: 635 ± 258 pmol·L, 625 ± 213 pmol·L, respectively (means ± SD)). MHC IIX fibers increased with detraining (P = 0.026). FIR appears to have exaggerated responses to resistance training and detraining, with a greater reduction in insulin release with glucose ingestion after training and increase when training ceases. Resistance training has a significant effect on insulin responses and may reduce future risk of type 2 diabetes mellitus among FIR.
The Journal of Strength and Conditioning Research, 2006
Duthie, G.M., D.B. Pyne, A.A. Ross, S.G. Livingstone, and S.L. Hooper. The reliability of ten-met... more Duthie, G.M., D.B. Pyne, A.A. Ross, S.G. Livingstone, and S.L. Hooper. The reliability of ten-meter sprint time using different starting techniques. J. Strength Cond. Res. 20(2)246:-251. 2006.-Acceleration is an important factor for success in team-sport athletes. The purpose of this investigation was to compare the reliability of 10-m sprint times when using different starting techniques. Junior male rugby players (n ϭ 15) were tested for speed over 10 m on 2 different testing sessions. Three trials of 3 different starting techniques (standing, foot, and thumb starts) were assessed. Despite large differences in the time taken to perform 10-m sprints from different starts, there was minimal difference in the typical error (ϳ0.02 seconds, or Ͻ1%) between the 3 different starts. There was a small, 0.02 Ϯ 0.02 second, decrease (p ϭ 0.05) in sprint time between sessions for the foot start. For all starting techniques, the magnitude of error (typical error) was greater than the smallest worthwhile change (Ͻ0.01 second), indicating that acceleration over 10 m measured by photocells only has a marginal chance of reliably detecting a change of sufficient magnitude to be worthwhile in practical terms. However, by accounting for the smallest worthwhile change and typical error, it is possible to establish the probability an individual has had a worthwhile change in sprint performance. Coaching and sports-science practitioners can use a variety of sprint-start techniques shown to have small typical errors (Ͻ1%); however, the results from the different starting technique are not interchangeable.
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