Nick Owen | Swansea University (original) (raw)

Papers by Nick Owen

Research paper thumbnail of Optimal Loading for Peak Power Output During the Hang Power Clean in Professional Rugby Players

International Journal of Sports Physiology and Performance, 2007

Purpose:The ability to develop high levels of muscle power is considered an essential component o... more Purpose:The ability to develop high levels of muscle power is considered an essential component of success in many sporting activities; however, the optimal load for the development of peak power during training remains controversial. The aim of the present study was to determine the optimal load required to observe peak power output (PPO) during the hang power clean in professional rugby players.Methods:Twelve professional rugby players performed hang power cleans on a portable force platform at loads of 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their predetermined 1-repetition maximum (1-RM) in a randomized and balanced order.Results:Relative load had a significant effect on power output, with peak values being obtained at 80% of the subjects’ 1-RM (4466 ± 477 W; P < .001). There was no significant difference, however, between the power outputs at 50%, 60%, 70%, or 90% 1-RM compared with 80% 1-RM. Peak force was produced at 90% 1-RM with relative load having a significant effect...

Research paper thumbnail of Validating Two Systems for Estimating Force and Power

International Journal of Sports Medicine, 2011

Myotest performs construct validity and reliability-Connecticut, USA • Validity of Myotest during... more Myotest performs construct validity and reliability-Connecticut, USA • Validity of Myotest during a vertical jump test-Dijon, FR • Effects of plyometric training using a portable self coaching system-Kyoto, JP

Research paper thumbnail of Influence of Postactivation Potentiation on Sprinting Performance in Professional Rugby Players

Journal of Strength and Conditioning Research, 2010

After a bout of highintensity exercise of short duration (preload stimulus), the muscle is in bot... more After a bout of highintensity exercise of short duration (preload stimulus), the muscle is in both a fatigued and potentiated (referred to as postactivation potentiation [PAP]) state. Consequently, subsequent muscle performance depends on the balance of these 2 factors. Although research has shown PAP to be an effective method of increasing power during both the squat jumps, little data exist on its effect on more functional activities such as sprinting. The present study aimed to determine the effect of PAP on sprint performance in professional rugby players. Sixteen professional male rugby players performed 5 10-m sprints (with a 5-m split): baseline, 4, 8, 12, and 16 minutes after the preload stimulus (1 set of 3 repetitions of the back squat at 91% 1 Repetition Maximum [RM]). There was no significant time effect over the duration of the study with regard to 5-m (p = 0.175) and 10-m sprint times (p = 0.401). However, when individual responses to PAP were taken into account, a significant improvement in sprint performance was observed over both 5 (Baseline: 1.09 6 0.06s vs. Best time: 1.05 6 0.05s, p = 0.002) and 10 m (Baseline: 1.83 6 0.08s vs. Best time: 1.79 6 0.08s, p = 0.003) compared with the baseline sprint. We conclude that sprinting performance is enhanced after a preload stimulus providing adequate and individualized recovery is given between the 2 activities, and this may have important implications for training speed.

Research paper thumbnail of Complex Training in Professional Rugby Players: Influence of Recovery Time on Upper-Body Power Output

Journal of Strength and Conditioning Research, 2009

After a bout of heavy resistance training (HRT), skeletal muscle is in both a fatigued and potent... more After a bout of heavy resistance training (HRT), skeletal muscle is in both a fatigued and potentiated state. Subsequent muscle performance depends on the balance between these 2 factors. To date, there is no uniform agreement about the recovery time required between the HRT and subsequent muscle performance to gain performance benefits in the upper body. The aim of the present study was to determine the recovery time required to observe enhanced upper-body muscle performance after HRT (i.e., complex training). Twenty-six professional rugby players performed a ballistic bench press (BBP) at baseline and at approximately 15 seconds and 4, 8, 12, 16, 20, and 24 minutes after HRT (3 sets of 3 repetitions at 87% 1 repetition maximum). Peak power output (PPO) and throw height were determined for all BBPs. A significant time effect with regard to PPO (F = 29.145, partial Eta2 = 0.538, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and throw height (F = 17.362, partial Eta2 = 0.410, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) was observed. Paired comparisons indicated a significant decrease in PPO and throw height in the BBP performed approximately 15 seconds after the HRT compared with the baseline BBP. After 8 minutes of recovery from the HRT, both PPO and throw height were significantly higher than the PPO and throw height recorded at baseline (e.g., PPO: 879 +/- 100 vs. 916 +/- 116 W, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). It was concluded that muscle performance can be significantly enhanced after bouts of HRT during a BBP providing that adequate recovery (8 min) is given between the HRT and the explosive activity.

Research paper thumbnail of Relationships Between Force–Time Characteristics of the Isometric Midthigh Pull and Dynamic Performance in Professional Rugby League Players

Journal of Strength and Conditioning Research, 2011

Relationships between forcetime characteristics of the isometric midthigh pull and dynamic perfor... more Relationships between forcetime characteristics of the isometric midthigh pull and dynamic performance in professional rugby league players. J Strength Cond Res 25(X): 000-000, 2011-There is considerable conflict within the literature regarding the relevance of isometric testing for the assessment of neuromuscular function within dynamic sports. The aim of this study was to determine the relationship between isometric measures of force development and dynamic performance. Thirty-nine professional rugby league players participated in this study. Forty-eight hours after trial familiarization, participants performed a maximal isometric midthigh pull, with ;120-130°bend at the knee, countermovement jump (CMJ), and a 10-m sprint. Force-time data were processed for peak force (PF), force at 100 milliseconds (F100ms), and peak rate of force development (PRFD). Analysis was carried out using Pearson's product moment correlation with significance set at p , 0.05. The PF was not related to dynamic performance; however, when expressed relative to body weight, it was significantly correlated with both 10-m time and CMJ height (r = 20.37 and 0.45, respectively, p , 0.05). The F100ms was inversely related to 10-m time (r = 20.54, p , 0.01); moreover, when expressed relative to body weight, it was significantly related to both 10-m time and CMJ height (r = 20.68 and 0.43, p , 0.01). In addition, significant correlations were found between PRFD and 10-m time (r = 20.66, p , 0.01) and CMJ height (r = 0.387, p , 0.01). In conclusion, this study provides evidence that measures of maximal strength and explosiveness from isometric force-time curves are related to jump and sprint acceleration performance in professional rugby league players.

Research paper thumbnail of The validity of Photogrammetric Osteological Analysis for Sex traits of Historic Crania

A poster presented at the British Association for Biological Anthropology and Osteoarchaeology (B... more A poster presented at the British Association for Biological Anthropology and Osteoarchaeology (BABAO) conference 2016 at University of Kent.A study into the use of photogrammetry for osteological analysis of remains from the Mary Rose, and a comparison to the analysis of the corresponding real crania. Four osteologists performed the study, examining 5 crania in the form of digital copies, and 5 different in the real, tactile format.The results showed that photogrammetry could be used for most sex trait determinants, though the lack of tactile analysis was an issue for some features.This study is part of a wider project that aims to analyse the use of photogrammetry for a number of cranial features, in addition to sex determination.

Research paper thumbnail of Strength and power predictors of sprinting performance in professional rugby players

The Journal of sports medicine and physical fitness

The ability to accelerate and attain high levels of speed is an essential component of success in... more The ability to accelerate and attain high levels of speed is an essential component of success in team sports; however, the physical qualities that underpin these activities remain unclear. This study aimed to determine some of the key strength and power predictors of speed within professional rugby union players. Twenty professional male rugby union players participated in this study. Subjects were tested for speed (0-10 m sprint and a flying 10 m sprint), strength (3 repetition maximum squat), lower body power (countermovement jumps [CMJ] and drop jumps [DJ]), reactive strength and leg spring stiffness. The strength and power variables were expressed as absolute values and relative values for analysis. Both relative strength (r=-0.55, P&amp;amp;lt;0.05) and relative power (-0.82, P&amp;amp;lt;0.01) were negatively correlated with 10 m time. Leg spring stiffness and DJ contact time were also related to the flying 10 m time (r=-0.46 and 0.47, respectively, P&amp;amp;lt;0.05) while reactive strength index was negatively related to both the 10 m and flying 10 m times (r=-0.60 and r=-0.62, P&amp;amp;lt;0.05). This study provides an insight into those physical attributes that underpin sprinting performance in professional rugby union players and specifically highlights the importance of relative strength and power in the expression and development of different speed components (e.g. acceleration, maximum velocity).

Research paper thumbnail of Gender differences in lower limb frontal plane kinematics during landing

Sports Biomechanics, 2008

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee a... more The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.

Research paper thumbnail of The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force During Landing From Volleyball Block Jumps

Research Quarterly for Exercise and Sport, 2010

The aim of this study was to examine the effect of opposition and gender on knee kinematics and g... more The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis system (120 Hz) was used to record knee kinematics, and a force platform (600 Hz) was used to record ground reaction force during landing. The results showed a significant effect for level of opposition in peak normalized ground reaction force (p = .04), knee flexion at ground contact (p = .003), maximum knee flexion (p = .001), and knee flexion range of motion (p = .003). There was a significant effect for gender in maximum knee flexion (p = .01), knee flexion range of motion (p = .001), maximum knee valgus angle (p = .001), and knee valgus range of motion (p = .001). The changes in landing biomechanics as a result of opposition suggest future research on landing mechanics should examine opposed exercises, because opposition may significantly alter neuromuscular responses.

Research paper thumbnail of Differences between the sexes in knee kinetics during landing from volleyball block jumps

European Journal of Sport Science, 2010

The aim of the study was to assess frontal and sagittal plane kinetics (normalized ground reactio... more The aim of the study was to assess frontal and sagittal plane kinetics (normalized ground reaction force and normalized knee moment) in male and female university volleyball players when performing opposed block jump landings. Females displayed a significantly lower normalized knee extension moment at the start of muscle latency than males. The greater normalized knee extension moment at the start of muscle latency in females suggests that, through practice, they may have developed a landing strategy that minimizes the moment acting about the knee in the sagittal plane to reduce the likely strain on the passive support structures. The time histories of the normalized knee moment in the frontal plane were different between males and females. The maximum normalized knee valgus moment was significantly greater in females than males. The significantly different maximum normalized knee valgus moment between males and females indicates a greater likelihood of overloading the muscles of the knee in females during landing, which, in turn, is likely to increase the strain on the passive support structures. The increased likely strain on the passive support structures of the knee in females could contribute to the higher incidence of non-contact anterior cruciate ligament injury in females compared with males.

Research paper thumbnail of Development of a Criterion Method to Determine Peak Mechanical Power Output in a Countermovement Jump

Journal of Strength and Conditioning Research, 2013

There is a general agreement that the most valid method of measuring peak lower-body mechanical p... more There is a general agreement that the most valid method of measuring peak lower-body mechanical power output (LBPP) in a countermovement jump (CMJ) is by analysis of the corresponding vertical component of the ground reaction force (VGRF)-time history of the jump. However, there is no published standard protocol. The purpose of this study was to establish a standard protocol. The variables necessary to define a valid and reliable CMJ method were: (a) vertical force range, (b) force sampling and integration frequency, (c) method of integration, (d) determination of body weight (BW), and (e) determination of the initiation of the CMJ. Countermovement jumps off a force platform (FP) were performed by 15 male professional rugby players. The 5 variables were then optimized to maximize the reliability and validity of the measure of LBPP. Errors of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1% (p ≤ 0.05) in the measurement of LBPP were obtained using the following specification: (a) 6 times BW (using a 16-bit analog to digital converter), (b) 1,000 Hz, (c) Simpson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s rule or the trapezoidal rule, (d) mean VGRF for 1 second of quiet standing immediately before jump signal, and (e) 30 ms before the instant BW ± 5 SD is exceeded after the jump signal. Peak lower-body power output was most sensitive to variables 4 and 5. It was concluded that this study has established a standard protocol for the criterion method of measuring peak power in a CMJ using an FP. As all other estimates and less reliable methods of determining LBPP in a CMJ rely on the FP method for calibration, it is proposed that this protocol be used as the basis of future criterion measures using a FP.

Research paper thumbnail of The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force During Landing From Volleyball Block Jumps

Research quarterly for …, 2010

The aim of this study was to examine the effect of opposition and gender on knee kinematics and g... more The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis system (120 Hz) was used to record knee kinematics, and a force platform (600 Hz) was used to record ground reaction force during landing. The results showed a significant effect for level of opposition in peak normalized ground reaction force (p = .04), knee flexion at ground contact (p = .003), maximum knee flexion (p = .001), and knee flexion range of motion (p = .003). There was a significant effect for gender in maximum knee flexion (p = .01), knee flexion range of motion (p = .001), maximum knee valgus angle (p = .001), and knee valgus range of motion (p = .001). The changes in landing biomechanics as a result of opposition suggest future research on landing mechanics should examine opposed exercises, because opposition may significantly alter neuromuscular responses.

Research paper thumbnail of Gender differences in lower limb frontal plane kinematics during landing

Sports Biomechanics, 2008

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee a... more The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.

Research paper thumbnail of Influence of recovery time on post-activation potentiation in professional rugby players

Journal of sports …, 2008

Following a bout of heavy resistance training, the muscle is in both a fatigued and potentiated s... more Following a bout of heavy resistance training, the muscle is in both a fatigued and potentiated state with subsequent muscle performance depending on the balance between these two factors. To date, there is no uniform agreement about the optimal acute recovery required between the heavy resistance training and subsequent muscle performance to gain performance benefits. The aim of the present study was to determine the recovery time required to observe enhanced muscle performance following a bout of heavy resistance training. Twenty professional rugby players performed a countermovement jump at baseline and approximately 15 s, 4, 8, 12, 16, 20, and 24 min after a bout of heavy resistance training (three sets of three repetitions at 87% one-repetition maximum squat). Power output, jump height, and peak rate of force development were determined for all countermovement jumps. Despite an initial decrease in countermovement jump performance after the heavy resistance training (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), participants&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance increased significantly following 8 min recovery (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) (i.e. jump height increased by 4.9%, s=3.0). The findings suggest that muscle performance during a countermovement jump can be markedly enhanced following bouts of heavy resistance training provided that adequate recovery (approximately 8 min) is allowed between the heavy resistance training and the explosive activity.

Research paper thumbnail of Postactivation potentiation in professional rugby players: Optimal recovery

The Journal of …, 2007

Following a bout of high-intensity exercise of short duration (preload stimulus), the muscle is i... more Following a bout of high-intensity exercise of short duration (preload stimulus), the muscle is in both a fatigued and a potentiated (referred to as postactivation potentiation) state. Consequently, subsequent muscle performance depends on the balance between these 2 factors. To date, there is no uniform agreement about the optimal recovery required between the preload stimulus and subsequent muscle performance to gain optimal performance benefits. The aim of the present study was to determine the optimal recovery time required to observe enhanced muscle performance following the preload stimulus. Twenty-three professional rugby players (13 senior international players) performed 7 countermovement jumps (CMJs) and 7 ballistic bench throws at the following time points after a preload stimulus (3 repetition maximum [3RM]): baseline, approximately 15 seconds, and 4, 8, 12, 16, and 20 minutes. Their peak power output (PPO) was determined at each time point. Statistical analyses revealed a significant decrease in PPO for both the upper (856 +/- 121 W vs. 816 +/- 121 W, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and the lower (4,568 +/- 509 W vs. 4,430 +/- 495 W, p = 0.005) body when the explosive activity was performed approximately 15 seconds after the preload stimulus. However, when 12 minutes was allowed between the preload stimulus and the CMJ and ballistic bench throws, PPO was increased by 8.0 +/- 8.0% and 5.3 +/- 4.5%, respectively. Based on the above results, we conclude that muscle performance (e.g., power) can be significantly enhanced following a bout of heavy exercise (preload stimulus) in both the upper and the lower body, provided that adequate recovery (8-12 minutes) is given between the preload stimulus and the explosive activity.

Research paper thumbnail of Effect of postactivation potentiation on swimming starts in international sprint swimmers

The aim of this study was to investigate the effects of postactivation potentiation (PAP) on swim... more The aim of this study was to investigate the effects of postactivation potentiation (PAP) on swim start performance (time to 15 m) in a group of international sprint swimmers. Nine international sprint swimmers (7 men and 2 women) volunteered and gave informed consent for this study, which was approved by the university ethics committee. Initially, swimmers performed a countermovement jump (CMJ) on a portable force platform (FP) at baseline and at the following time points ∼15 seconds, 4, 8, 12, and 16 minutes after a PAP stimulus (1 set of 3 repetitions at 87% 1 repetition maximum [RM]) to individually determine the recovery time required to observe enhanced muscle performance. On 2 additional days, swimmers performed a swim start to 15 m under 50-m freestyle race conditions, which was preceded by either their individualized race specific warm-up or a PAP stimulus (1 set of 3 repetitions at 87% 1RM). Both trials were recorded on 2 cameras operating at 50 Hz with camera 1 located at the start and camera 2 at the 15-m mark. Peak vertical force (PVF) and peak horizontal force (PHF) were measured during all swim starts from a portable FP placed on top of the swim block. A repeated measures analysis of variance revealed a significant time effect with regard to power output (PO) (F = 20.963, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and jump height (JH) (F = 14.634, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) with a paired comparison indicating a significant increase in PO and JH after 8 minutes of recovery from the PAP stimulus. There was a significant increase in both PHF and PVF after the PAP stimulus compared to the swim-specific warm-up during the swim start (PHF 770 ± 228 vs. 814 ± 263 N, p = 0.018; PVF: 1,462 ± 280 vs. 1,518 ± 311 N, p = 0.038); however, time to 15 m was the same when both starts were compared (7.1 ± 0.8 vs. 7.1 ± 0.8 seconds, p = 0.447). The results from this study indicate that muscle performance during a CMJ is enhanced after a PAP stimulus providing adequate recovery (∼8 minutes) is given between the 2 activities. In addition, this study demonstrated that swimmers performed equally well in terms of time to 15 m when a PAP stimulus was compared to their individualized race specific warm-up and indicates that PAP may be a useful addition to a warm-up protocol before races. However, more research is required to fully understand the role PAP plays in swim performance.

Research paper thumbnail of Optimal Loading for Peak Power Output During the Hang Power Clean in Professional Rugby Players

International Journal of Sports Physiology and Performance, 2007

Purpose:The ability to develop high levels of muscle power is considered an essential component o... more Purpose:The ability to develop high levels of muscle power is considered an essential component of success in many sporting activities; however, the optimal load for the development of peak power during training remains controversial. The aim of the present study was to determine the optimal load required to observe peak power output (PPO) during the hang power clean in professional rugby players.Methods:Twelve professional rugby players performed hang power cleans on a portable force platform at loads of 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their predetermined 1-repetition maximum (1-RM) in a randomized and balanced order.Results:Relative load had a significant effect on power output, with peak values being obtained at 80% of the subjects’ 1-RM (4466 ± 477 W; P < .001). There was no significant difference, however, between the power outputs at 50%, 60%, 70%, or 90% 1-RM compared with 80% 1-RM. Peak force was produced at 90% 1-RM with relative load having a significant effect...

Research paper thumbnail of Validating Two Systems for Estimating Force and Power

International Journal of Sports Medicine, 2011

Myotest performs construct validity and reliability-Connecticut, USA • Validity of Myotest during... more Myotest performs construct validity and reliability-Connecticut, USA • Validity of Myotest during a vertical jump test-Dijon, FR • Effects of plyometric training using a portable self coaching system-Kyoto, JP

Research paper thumbnail of Influence of Postactivation Potentiation on Sprinting Performance in Professional Rugby Players

Journal of Strength and Conditioning Research, 2010

After a bout of highintensity exercise of short duration (preload stimulus), the muscle is in bot... more After a bout of highintensity exercise of short duration (preload stimulus), the muscle is in both a fatigued and potentiated (referred to as postactivation potentiation [PAP]) state. Consequently, subsequent muscle performance depends on the balance of these 2 factors. Although research has shown PAP to be an effective method of increasing power during both the squat jumps, little data exist on its effect on more functional activities such as sprinting. The present study aimed to determine the effect of PAP on sprint performance in professional rugby players. Sixteen professional male rugby players performed 5 10-m sprints (with a 5-m split): baseline, 4, 8, 12, and 16 minutes after the preload stimulus (1 set of 3 repetitions of the back squat at 91% 1 Repetition Maximum [RM]). There was no significant time effect over the duration of the study with regard to 5-m (p = 0.175) and 10-m sprint times (p = 0.401). However, when individual responses to PAP were taken into account, a significant improvement in sprint performance was observed over both 5 (Baseline: 1.09 6 0.06s vs. Best time: 1.05 6 0.05s, p = 0.002) and 10 m (Baseline: 1.83 6 0.08s vs. Best time: 1.79 6 0.08s, p = 0.003) compared with the baseline sprint. We conclude that sprinting performance is enhanced after a preload stimulus providing adequate and individualized recovery is given between the 2 activities, and this may have important implications for training speed.

Research paper thumbnail of Complex Training in Professional Rugby Players: Influence of Recovery Time on Upper-Body Power Output

Journal of Strength and Conditioning Research, 2009

After a bout of heavy resistance training (HRT), skeletal muscle is in both a fatigued and potent... more After a bout of heavy resistance training (HRT), skeletal muscle is in both a fatigued and potentiated state. Subsequent muscle performance depends on the balance between these 2 factors. To date, there is no uniform agreement about the recovery time required between the HRT and subsequent muscle performance to gain performance benefits in the upper body. The aim of the present study was to determine the recovery time required to observe enhanced upper-body muscle performance after HRT (i.e., complex training). Twenty-six professional rugby players performed a ballistic bench press (BBP) at baseline and at approximately 15 seconds and 4, 8, 12, 16, 20, and 24 minutes after HRT (3 sets of 3 repetitions at 87% 1 repetition maximum). Peak power output (PPO) and throw height were determined for all BBPs. A significant time effect with regard to PPO (F = 29.145, partial Eta2 = 0.538, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and throw height (F = 17.362, partial Eta2 = 0.410, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) was observed. Paired comparisons indicated a significant decrease in PPO and throw height in the BBP performed approximately 15 seconds after the HRT compared with the baseline BBP. After 8 minutes of recovery from the HRT, both PPO and throw height were significantly higher than the PPO and throw height recorded at baseline (e.g., PPO: 879 +/- 100 vs. 916 +/- 116 W, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). It was concluded that muscle performance can be significantly enhanced after bouts of HRT during a BBP providing that adequate recovery (8 min) is given between the HRT and the explosive activity.

Research paper thumbnail of Relationships Between Force–Time Characteristics of the Isometric Midthigh Pull and Dynamic Performance in Professional Rugby League Players

Journal of Strength and Conditioning Research, 2011

Relationships between forcetime characteristics of the isometric midthigh pull and dynamic perfor... more Relationships between forcetime characteristics of the isometric midthigh pull and dynamic performance in professional rugby league players. J Strength Cond Res 25(X): 000-000, 2011-There is considerable conflict within the literature regarding the relevance of isometric testing for the assessment of neuromuscular function within dynamic sports. The aim of this study was to determine the relationship between isometric measures of force development and dynamic performance. Thirty-nine professional rugby league players participated in this study. Forty-eight hours after trial familiarization, participants performed a maximal isometric midthigh pull, with ;120-130°bend at the knee, countermovement jump (CMJ), and a 10-m sprint. Force-time data were processed for peak force (PF), force at 100 milliseconds (F100ms), and peak rate of force development (PRFD). Analysis was carried out using Pearson's product moment correlation with significance set at p , 0.05. The PF was not related to dynamic performance; however, when expressed relative to body weight, it was significantly correlated with both 10-m time and CMJ height (r = 20.37 and 0.45, respectively, p , 0.05). The F100ms was inversely related to 10-m time (r = 20.54, p , 0.01); moreover, when expressed relative to body weight, it was significantly related to both 10-m time and CMJ height (r = 20.68 and 0.43, p , 0.01). In addition, significant correlations were found between PRFD and 10-m time (r = 20.66, p , 0.01) and CMJ height (r = 0.387, p , 0.01). In conclusion, this study provides evidence that measures of maximal strength and explosiveness from isometric force-time curves are related to jump and sprint acceleration performance in professional rugby league players.

Research paper thumbnail of The validity of Photogrammetric Osteological Analysis for Sex traits of Historic Crania

A poster presented at the British Association for Biological Anthropology and Osteoarchaeology (B... more A poster presented at the British Association for Biological Anthropology and Osteoarchaeology (BABAO) conference 2016 at University of Kent.A study into the use of photogrammetry for osteological analysis of remains from the Mary Rose, and a comparison to the analysis of the corresponding real crania. Four osteologists performed the study, examining 5 crania in the form of digital copies, and 5 different in the real, tactile format.The results showed that photogrammetry could be used for most sex trait determinants, though the lack of tactile analysis was an issue for some features.This study is part of a wider project that aims to analyse the use of photogrammetry for a number of cranial features, in addition to sex determination.

Research paper thumbnail of Strength and power predictors of sprinting performance in professional rugby players

The Journal of sports medicine and physical fitness

The ability to accelerate and attain high levels of speed is an essential component of success in... more The ability to accelerate and attain high levels of speed is an essential component of success in team sports; however, the physical qualities that underpin these activities remain unclear. This study aimed to determine some of the key strength and power predictors of speed within professional rugby union players. Twenty professional male rugby union players participated in this study. Subjects were tested for speed (0-10 m sprint and a flying 10 m sprint), strength (3 repetition maximum squat), lower body power (countermovement jumps [CMJ] and drop jumps [DJ]), reactive strength and leg spring stiffness. The strength and power variables were expressed as absolute values and relative values for analysis. Both relative strength (r=-0.55, P&amp;amp;lt;0.05) and relative power (-0.82, P&amp;amp;lt;0.01) were negatively correlated with 10 m time. Leg spring stiffness and DJ contact time were also related to the flying 10 m time (r=-0.46 and 0.47, respectively, P&amp;amp;lt;0.05) while reactive strength index was negatively related to both the 10 m and flying 10 m times (r=-0.60 and r=-0.62, P&amp;amp;lt;0.05). This study provides an insight into those physical attributes that underpin sprinting performance in professional rugby union players and specifically highlights the importance of relative strength and power in the expression and development of different speed components (e.g. acceleration, maximum velocity).

Research paper thumbnail of Gender differences in lower limb frontal plane kinematics during landing

Sports Biomechanics, 2008

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee a... more The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.

Research paper thumbnail of The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force During Landing From Volleyball Block Jumps

Research Quarterly for Exercise and Sport, 2010

The aim of this study was to examine the effect of opposition and gender on knee kinematics and g... more The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis system (120 Hz) was used to record knee kinematics, and a force platform (600 Hz) was used to record ground reaction force during landing. The results showed a significant effect for level of opposition in peak normalized ground reaction force (p = .04), knee flexion at ground contact (p = .003), maximum knee flexion (p = .001), and knee flexion range of motion (p = .003). There was a significant effect for gender in maximum knee flexion (p = .01), knee flexion range of motion (p = .001), maximum knee valgus angle (p = .001), and knee valgus range of motion (p = .001). The changes in landing biomechanics as a result of opposition suggest future research on landing mechanics should examine opposed exercises, because opposition may significantly alter neuromuscular responses.

Research paper thumbnail of Differences between the sexes in knee kinetics during landing from volleyball block jumps

European Journal of Sport Science, 2010

The aim of the study was to assess frontal and sagittal plane kinetics (normalized ground reactio... more The aim of the study was to assess frontal and sagittal plane kinetics (normalized ground reaction force and normalized knee moment) in male and female university volleyball players when performing opposed block jump landings. Females displayed a significantly lower normalized knee extension moment at the start of muscle latency than males. The greater normalized knee extension moment at the start of muscle latency in females suggests that, through practice, they may have developed a landing strategy that minimizes the moment acting about the knee in the sagittal plane to reduce the likely strain on the passive support structures. The time histories of the normalized knee moment in the frontal plane were different between males and females. The maximum normalized knee valgus moment was significantly greater in females than males. The significantly different maximum normalized knee valgus moment between males and females indicates a greater likelihood of overloading the muscles of the knee in females during landing, which, in turn, is likely to increase the strain on the passive support structures. The increased likely strain on the passive support structures of the knee in females could contribute to the higher incidence of non-contact anterior cruciate ligament injury in females compared with males.

Research paper thumbnail of Development of a Criterion Method to Determine Peak Mechanical Power Output in a Countermovement Jump

Journal of Strength and Conditioning Research, 2013

There is a general agreement that the most valid method of measuring peak lower-body mechanical p... more There is a general agreement that the most valid method of measuring peak lower-body mechanical power output (LBPP) in a countermovement jump (CMJ) is by analysis of the corresponding vertical component of the ground reaction force (VGRF)-time history of the jump. However, there is no published standard protocol. The purpose of this study was to establish a standard protocol. The variables necessary to define a valid and reliable CMJ method were: (a) vertical force range, (b) force sampling and integration frequency, (c) method of integration, (d) determination of body weight (BW), and (e) determination of the initiation of the CMJ. Countermovement jumps off a force platform (FP) were performed by 15 male professional rugby players. The 5 variables were then optimized to maximize the reliability and validity of the measure of LBPP. Errors of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1% (p ≤ 0.05) in the measurement of LBPP were obtained using the following specification: (a) 6 times BW (using a 16-bit analog to digital converter), (b) 1,000 Hz, (c) Simpson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s rule or the trapezoidal rule, (d) mean VGRF for 1 second of quiet standing immediately before jump signal, and (e) 30 ms before the instant BW ± 5 SD is exceeded after the jump signal. Peak lower-body power output was most sensitive to variables 4 and 5. It was concluded that this study has established a standard protocol for the criterion method of measuring peak power in a CMJ using an FP. As all other estimates and less reliable methods of determining LBPP in a CMJ rely on the FP method for calibration, it is proposed that this protocol be used as the basis of future criterion measures using a FP.

Research paper thumbnail of The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force During Landing From Volleyball Block Jumps

Research quarterly for …, 2010

The aim of this study was to examine the effect of opposition and gender on knee kinematics and g... more The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis system (120 Hz) was used to record knee kinematics, and a force platform (600 Hz) was used to record ground reaction force during landing. The results showed a significant effect for level of opposition in peak normalized ground reaction force (p = .04), knee flexion at ground contact (p = .003), maximum knee flexion (p = .001), and knee flexion range of motion (p = .003). There was a significant effect for gender in maximum knee flexion (p = .01), knee flexion range of motion (p = .001), maximum knee valgus angle (p = .001), and knee valgus range of motion (p = .001). The changes in landing biomechanics as a result of opposition suggest future research on landing mechanics should examine opposed exercises, because opposition may significantly alter neuromuscular responses.

Research paper thumbnail of Gender differences in lower limb frontal plane kinematics during landing

Sports Biomechanics, 2008

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee a... more The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.

Research paper thumbnail of Influence of recovery time on post-activation potentiation in professional rugby players

Journal of sports …, 2008

Following a bout of heavy resistance training, the muscle is in both a fatigued and potentiated s... more Following a bout of heavy resistance training, the muscle is in both a fatigued and potentiated state with subsequent muscle performance depending on the balance between these two factors. To date, there is no uniform agreement about the optimal acute recovery required between the heavy resistance training and subsequent muscle performance to gain performance benefits. The aim of the present study was to determine the recovery time required to observe enhanced muscle performance following a bout of heavy resistance training. Twenty professional rugby players performed a countermovement jump at baseline and approximately 15 s, 4, 8, 12, 16, 20, and 24 min after a bout of heavy resistance training (three sets of three repetitions at 87% one-repetition maximum squat). Power output, jump height, and peak rate of force development were determined for all countermovement jumps. Despite an initial decrease in countermovement jump performance after the heavy resistance training (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), participants&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance increased significantly following 8 min recovery (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) (i.e. jump height increased by 4.9%, s=3.0). The findings suggest that muscle performance during a countermovement jump can be markedly enhanced following bouts of heavy resistance training provided that adequate recovery (approximately 8 min) is allowed between the heavy resistance training and the explosive activity.

Research paper thumbnail of Postactivation potentiation in professional rugby players: Optimal recovery

The Journal of …, 2007

Following a bout of high-intensity exercise of short duration (preload stimulus), the muscle is i... more Following a bout of high-intensity exercise of short duration (preload stimulus), the muscle is in both a fatigued and a potentiated (referred to as postactivation potentiation) state. Consequently, subsequent muscle performance depends on the balance between these 2 factors. To date, there is no uniform agreement about the optimal recovery required between the preload stimulus and subsequent muscle performance to gain optimal performance benefits. The aim of the present study was to determine the optimal recovery time required to observe enhanced muscle performance following the preload stimulus. Twenty-three professional rugby players (13 senior international players) performed 7 countermovement jumps (CMJs) and 7 ballistic bench throws at the following time points after a preload stimulus (3 repetition maximum [3RM]): baseline, approximately 15 seconds, and 4, 8, 12, 16, and 20 minutes. Their peak power output (PPO) was determined at each time point. Statistical analyses revealed a significant decrease in PPO for both the upper (856 +/- 121 W vs. 816 +/- 121 W, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and the lower (4,568 +/- 509 W vs. 4,430 +/- 495 W, p = 0.005) body when the explosive activity was performed approximately 15 seconds after the preload stimulus. However, when 12 minutes was allowed between the preload stimulus and the CMJ and ballistic bench throws, PPO was increased by 8.0 +/- 8.0% and 5.3 +/- 4.5%, respectively. Based on the above results, we conclude that muscle performance (e.g., power) can be significantly enhanced following a bout of heavy exercise (preload stimulus) in both the upper and the lower body, provided that adequate recovery (8-12 minutes) is given between the preload stimulus and the explosive activity.

Research paper thumbnail of Effect of postactivation potentiation on swimming starts in international sprint swimmers

The aim of this study was to investigate the effects of postactivation potentiation (PAP) on swim... more The aim of this study was to investigate the effects of postactivation potentiation (PAP) on swim start performance (time to 15 m) in a group of international sprint swimmers. Nine international sprint swimmers (7 men and 2 women) volunteered and gave informed consent for this study, which was approved by the university ethics committee. Initially, swimmers performed a countermovement jump (CMJ) on a portable force platform (FP) at baseline and at the following time points ∼15 seconds, 4, 8, 12, and 16 minutes after a PAP stimulus (1 set of 3 repetitions at 87% 1 repetition maximum [RM]) to individually determine the recovery time required to observe enhanced muscle performance. On 2 additional days, swimmers performed a swim start to 15 m under 50-m freestyle race conditions, which was preceded by either their individualized race specific warm-up or a PAP stimulus (1 set of 3 repetitions at 87% 1RM). Both trials were recorded on 2 cameras operating at 50 Hz with camera 1 located at the start and camera 2 at the 15-m mark. Peak vertical force (PVF) and peak horizontal force (PHF) were measured during all swim starts from a portable FP placed on top of the swim block. A repeated measures analysis of variance revealed a significant time effect with regard to power output (PO) (F = 20.963, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and jump height (JH) (F = 14.634, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) with a paired comparison indicating a significant increase in PO and JH after 8 minutes of recovery from the PAP stimulus. There was a significant increase in both PHF and PVF after the PAP stimulus compared to the swim-specific warm-up during the swim start (PHF 770 ± 228 vs. 814 ± 263 N, p = 0.018; PVF: 1,462 ± 280 vs. 1,518 ± 311 N, p = 0.038); however, time to 15 m was the same when both starts were compared (7.1 ± 0.8 vs. 7.1 ± 0.8 seconds, p = 0.447). The results from this study indicate that muscle performance during a CMJ is enhanced after a PAP stimulus providing adequate recovery (∼8 minutes) is given between the 2 activities. In addition, this study demonstrated that swimmers performed equally well in terms of time to 15 m when a PAP stimulus was compared to their individualized race specific warm-up and indicates that PAP may be a useful addition to a warm-up protocol before races. However, more research is required to fully understand the role PAP plays in swim performance.