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Predictors of individual player performance in junior Australian football
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Thursday 16 October Posters / Journal of Science and Medicine in Sport 18S (2014) e72–e107
recovery period were set at maximum oxygen uptake (100% of VO2 max) and at 50% of VO2 max, respectively. Oxygen uptake was determined using a gas analysis system, while oxyhemoglobin (O2 Hb) and deoxyhemoglobin (HHb) levels at the left vastus lateralis muscle were determined using a NIRS device during interval swimming. Blood lactate accumulations were measured at 1, 3, 5 min after each trial completion. Results: Mean value for oxygen uptake during the rest period was higher with active recovery condition than passive recovery condition. In addition, O2 Hb variations during rest period for active recovery condition were significantly lower than for passive recovery condition. On the contrary, HHb variations during rest period for active recovery condition were significantly higher than for passive recovery condition. Blood lactate accumulations was not significantly different between recovery conditions. Discussion: Active recovery during interval swimming was associated with higher oxygen uptake response and lower muscular reoxygenation. http://dx.doi.org/10.1016/j.jsams.2014.11.331 26 Predictors of individual player performance in junior Australian football C. Tangalos 1 , S. Robertson 1 , M. Spittle 1,2 , P. Gastin 1,∗ 1 Centre for Exercise and Sport Science, Deakin University, Australia 2 College of Sport and Exercise Science, Victoria University, Australia
Introduction: Player performance outcomes and contributors to success in junior AF are not well understood. An increased evidence base that focuses on the foundation level of the participation and performance pathway in AF has implications for the development of coaching priorities (e.g., physical or technical) and player retention strategies. Purpose: The aim of this study was to investigate the relationships between indices of fitness (speed, power and endurance) and skill (coach’s rating) on player match performance (disposals and effective disposals) in junior AF. Methods: Junior male AF players (n = 156, 10–15 years old) were recruited from 12 teams from a single amateur recreational AF club located in metropolitan Victoria. All players were tested for fitness (20 m sprint, vertical jump, 20 m multi-stage shuttle run) and rated by their coach on a 6-point Likert scale for skill (within each team in comparison to their peers). Player performance was assessed during a single match in which disposals and their effectiveness were coded from a video recording. Results: Coach’s rating of skill, followed by running endurance (20 m shuttle), predicted in total 46% and 48% of the variance in disposals and number of effective disposals, respectively. None of the skill or fitness variables adequately explained the percentage of effective disposals. Discussion: Skill development should be considered a high priority by coaches in junior AF, along with running endurance. Findings also suggest that more appropriate measures of skill (e.g., perceptual-cognitive tests) may be necessary as coach rating of skill appeared to be more related to the ability to gain possession (i.e., the number of disposals) rather than the ability to dispose of the football with skill (i.e., the percentage of effective disposals). http://dx.doi.org/10.1016/j.jsams.2014.11.332
27 Current warm-up practices and the contemporary issues faced by elite swimming coaches C. McGowan 1,∗ , B. Rattray 1 , K. Thompson 1 , D. Pyne 2 , J. Raglin 3 1
University of Canberra, Australia Australian Institute of Sport, Australia 3 Indiana University Bloomington, United States 2
Background: Only limited scientific evidence is available on the “best practices” for competition warm-up design in elite swimming. Given the recent occurrence of several major technical and technological changes in elite swimming competitions, coaches are left to draw upon outdated guidelines when designing athlete’s warm-up strategies. The aim of the present study was to describe current warm-up practices and identify contemporary issues faced by elite swimming coaches within the competition environment. Methods: A total of 46 state- to international-level swimming coaches from Australia, Britain and Canada completed a questionnaire consisting of 18 questions (9 multiple choice and 9 short answer) relating to their views on the value of competition warmups, the volume, intensity and recovery used in their pool and out of pool warm-ups and other related issues. Results: The coaches identified three main aims of the competition warm-up: physiological (to elevate body temperature and increase muscle activation), physical (to increase “feel” of the water) and mental (to improve focus and relax nerves). Total warm-up volume employed ranged from 800 to 2400 m, beginning with 300–900 m of continuous, low intensity (typically 30–70% of perceived exertion) swimming, followed by 200–600 m of increasing intensity (60–90%) with efforts lasting 100–300 m in length and concluding with several 25–50 m race or near race pace (90–100%) efforts totalling 100–300 m. Some land-based warm-up strategies are encouraged but are typically limited to static stretching and core activation exercises. The preferred time frame between pool warmup end and race start (transition phase) was 20 min. Extended marshalling periods (>15 min), delayed competition schedules and the lengthy time required to change into racing suits (>10 min) were all identified as issues faced during competition. These issues extend the transition phase beyond the preferred time frame. Discussion: Although pool warm-ups are thoroughly prescribed they do not appear to address issues relating to the extended duration of the marshalling periods and the time required to don racing suits. Elevated body temperatures in addition to increased muscle activation are two of the main purported benefits of warming-up but have a limited effect beyond ∼15–20 min following exercise cessation, a scenario common in the contemporary swimming environment. Given these constraints, sport scientists should investigate methods for improving body temperature maintenance such as passive heating techniques and muscle reactivation strategies like postactivation potentiation during the transition phase. These approaches may lead to the optimisation of competition performance in the contemporary swimming environment. http://dx.doi.org/10.1016/j.jsams.2014.11.333
Thursday 16 October Posters / Journal of Science and Medicine in Sport 18S (2014) e72–e107
recovery period were set at maximum oxygen uptake (100% of VO2 max) and at 50% of VO2 max, respectively. Oxygen uptake was determined using a gas analysis system, while oxyhemoglobin (O2 Hb) and deoxyhemoglobin (HHb) levels at the left vastus lateralis muscle were determined using a NIRS device during interval swimming. Blood lactate accumulations were measured at 1, 3, 5 min after each trial completion. Results: Mean value for oxygen uptake during the rest period was higher with active recovery condition than passive recovery condition. In addition, O2 Hb variations during rest period for active recovery condition were significantly lower than for passive recovery condition. On the contrary, HHb variations during rest period for active recovery condition were significantly higher than for passive recovery condition. Blood lactate accumulations was not significantly different between recovery conditions. Discussion: Active recovery during interval swimming was associated with higher oxygen uptake response and lower muscular reoxygenation. http://dx.doi.org/10.1016/j.jsams.2014.11.331 26 Predictors of individual player performance in junior Australian football C. Tangalos 1 , S. Robertson 1 , M. Spittle 1,2 , P. Gastin 1,∗ 1 Centre for Exercise and Sport Science, Deakin University, Australia 2 College of Sport and Exercise Science, Victoria University, Australia
Introduction: Player performance outcomes and contributors to success in junior AF are not well understood. An increased evidence base that focuses on the foundation level of the participation and performance pathway in AF has implications for the development of coaching priorities (e.g., physical or technical) and player retention strategies. Purpose: The aim of this study was to investigate the relationships between indices of fitness (speed, power and endurance) and skill (coach’s rating) on player match performance (disposals and effective disposals) in junior AF. Methods: Junior male AF players (n = 156, 10–15 years old) were recruited from 12 teams from a single amateur recreational AF club located in metropolitan Victoria. All players were tested for fitness (20 m sprint, vertical jump, 20 m multi-stage shuttle run) and rated by their coach on a 6-point Likert scale for skill (within each team in comparison to their peers). Player performance was assessed during a single match in which disposals and their effectiveness were coded from a video recording. Results: Coach’s rating of skill, followed by running endurance (20 m shuttle), predicted in total 46% and 48% of the variance in disposals and number of effective disposals, respectively. None of the skill or fitness variables adequately explained the percentage of effective disposals. Discussion: Skill development should be considered a high priority by coaches in junior AF, along with running endurance. Findings also suggest that more appropriate measures of skill (e.g., perceptual-cognitive tests) may be necessary as coach rating of skill appeared to be more related to the ability to gain possession (i.e., the number of disposals) rather than the ability to dispose of the football with skill (i.e., the percentage of effective disposals). http://dx.doi.org/10.1016/j.jsams.2014.11.332
27 Current warm-up practices and the contemporary issues faced by elite swimming coaches C. McGowan 1,∗ , B. Rattray 1 , K. Thompson 1 , D. Pyne 2 , J. Raglin 3 1
University of Canberra, Australia Australian Institute of Sport, Australia 3 Indiana University Bloomington, United States 2
Background: Only limited scientific evidence is available on the “best practices” for competition warm-up design in elite swimming. Given the recent occurrence of several major technical and technological changes in elite swimming competitions, coaches are left to draw upon outdated guidelines when designing athlete’s warm-up strategies. The aim of the present study was to describe current warm-up practices and identify contemporary issues faced by elite swimming coaches within the competition environment. Methods: A total of 46 state- to international-level swimming coaches from Australia, Britain and Canada completed a questionnaire consisting of 18 questions (9 multiple choice and 9 short answer) relating to their views on the value of competition warmups, the volume, intensity and recovery used in their pool and out of pool warm-ups and other related issues. Results: The coaches identified three main aims of the competition warm-up: physiological (to elevate body temperature and increase muscle activation), physical (to increase “feel” of the water) and mental (to improve focus and relax nerves). Total warm-up volume employed ranged from 800 to 2400 m, beginning with 300–900 m of continuous, low intensity (typically 30–70% of perceived exertion) swimming, followed by 200–600 m of increasing intensity (60–90%) with efforts lasting 100–300 m in length and concluding with several 25–50 m race or near race pace (90–100%) efforts totalling 100–300 m. Some land-based warm-up strategies are encouraged but are typically limited to static stretching and core activation exercises. The preferred time frame between pool warmup end and race start (transition phase) was 20 min. Extended marshalling periods (>15 min), delayed competition schedules and the lengthy time required to change into racing suits (>10 min) were all identified as issues faced during competition. These issues extend the transition phase beyond the preferred time frame. Discussion: Although pool warm-ups are thoroughly prescribed they do not appear to address issues relating to the extended duration of the marshalling periods and the time required to don racing suits. Elevated body temperatures in addition to increased muscle activation are two of the main purported benefits of warming-up but have a limited effect beyond ∼15–20 min following exercise cessation, a scenario common in the contemporary swimming environment. Given these constraints, sport scientists should investigate methods for improving body temperature maintenance such as passive heating techniques and muscle reactivation strategies like postactivation potentiation during the transition phase. These approaches may lead to the optimisation of competition performance in the contemporary swimming environment. http://dx.doi.org/10.1016/j.jsams.2014.11.333