A deterministic model of the vertical jump : Implications for training
- Ham, Daniel, Knez, Wade, Young, Warren
- Authors: Ham, Daniel , Knez, Wade , Young, Warren
- Date: 2007
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 21, no. 3 (2007), p. 967-972
- Full Text:
- Reviewed:
- Description: A deterministic model of the vertical jump: implications for training. J. Strength Cond. Res. 21(3):967-972. 2007. - Increasing vertical jump height is a critical component for performance enhancement in many sports. It takes on a number of different forms and conditions, including double and single legged jumps and stationary and run-up jumps. In an attempt to understand the factors that influence vertical jump performance, an extensive analysis was undertaken using the deterministic model. Once identified, practical training strategies enabling improvement in these factors were elucidated. Our analysis showed that a successful vertical jump performance was the result of a complex interplay of run-up speed, reactive strength, concentric action power of the take-off leg(s), hip flexors, shoulders, body position, body mass, and take-off time. Of special interest, our analysis showed that the concentric action power of the legs was the critical factor affecting stationary double leg vertical jumps, whereas reactive strength was the critical component for a single leg jump from a run-up. © 2007 National Strength & Conditioning Association.
- Description: C1
- Description: 2003005651
- Authors: Ham, Daniel , Knez, Wade , Young, Warren
- Date: 2007
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 21, no. 3 (2007), p. 967-972
- Full Text:
- Reviewed:
- Description: A deterministic model of the vertical jump: implications for training. J. Strength Cond. Res. 21(3):967-972. 2007. - Increasing vertical jump height is a critical component for performance enhancement in many sports. It takes on a number of different forms and conditions, including double and single legged jumps and stationary and run-up jumps. In an attempt to understand the factors that influence vertical jump performance, an extensive analysis was undertaken using the deterministic model. Once identified, practical training strategies enabling improvement in these factors were elucidated. Our analysis showed that a successful vertical jump performance was the result of a complex interplay of run-up speed, reactive strength, concentric action power of the take-off leg(s), hip flexors, shoulders, body position, body mass, and take-off time. Of special interest, our analysis showed that the concentric action power of the legs was the critical factor affecting stationary double leg vertical jumps, whereas reactive strength was the critical component for a single leg jump from a run-up. © 2007 National Strength & Conditioning Association.
- Description: C1
- Description: 2003005651
A review of agility : Practical applications for strength and conditioning
- Young, Warren, Farrow, Damian
- Authors: Young, Warren , Farrow, Damian
- Date: 2006
- Type: Text , Journal article
- Relation: Strength and Conditioning Journal Vol. 28, no. 5 (2006), p. 24-29
- Full Text:
- Reviewed:
- Description: Agility is an important component of many sports but has not been extensively researched. The various components that contribute to agility performance are discussed and training guidelines are provided. There appears to be limited transfer to agility performance from straight sprint training as well as from general strength training. The principle of training specificity is emphasized to achieve maximum transfer to on-field performance.
- Description: C1
- Description: 2003002120
- Authors: Young, Warren , Farrow, Damian
- Date: 2006
- Type: Text , Journal article
- Relation: Strength and Conditioning Journal Vol. 28, no. 5 (2006), p. 24-29
- Full Text:
- Reviewed:
- Description: Agility is an important component of many sports but has not been extensively researched. The various components that contribute to agility performance are discussed and training guidelines are provided. There appears to be limited transfer to agility performance from straight sprint training as well as from general strength training. The principle of training specificity is emphasized to achieve maximum transfer to on-field performance.
- Description: C1
- Description: 2003002120
Acute effects of static stretching on hip flexor and quadriceps flexibility, range of motion and foot speed in kicking a football
- Young, Warren, Clothier, Peter, Otago, Leonie, Bruce, Lyndell, Liddell, David
- Authors: Young, Warren , Clothier, Peter , Otago, Leonie , Bruce, Lyndell , Liddell, David
- Date: 2004
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 7, no. 1 (Mar 2004), p. 23-31
- Full Text:
- Reviewed:
- Description: The purpose of this research was to determine the effect of static stretching in a warm-up on hip flexor and quadriceps flexibility as measured by a modified Thomas test and on range of motion (ROM) of the leg and foot speed at impact in kicking a football with maximum effort. Sixteen Australian Rules (AR) footballers performed two different warm-ups on different days. One warm-up involved five minutes of sub-maximum running followed by seven practice kicks, while the other also included 4.5 minutes static stretching of the hip flexors and quadriceps after the running. A modified Thomas test was conduced before and after each warm-up. Players performed maximum effort drop punt kicks into a net while being videotaped to determine the ROM of the kicking leg and foot speed at impact with the ball. There were no significant changes in flexibility (p>0.05) as a result of either warm-up and there were no significant differences between the warm-ups in the kicking variables (p>0.05). It was concluded that the Thomas test may not have been sensitive to possible acute changes in flexibility from the warm-ups, and that stretching had no influence on kicking ROM or foot speed, possibly because of the complexity of the kicking skill.
- Description: C1
- Description: 2003000977
- Authors: Young, Warren , Clothier, Peter , Otago, Leonie , Bruce, Lyndell , Liddell, David
- Date: 2004
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 7, no. 1 (Mar 2004), p. 23-31
- Full Text:
- Reviewed:
- Description: The purpose of this research was to determine the effect of static stretching in a warm-up on hip flexor and quadriceps flexibility as measured by a modified Thomas test and on range of motion (ROM) of the leg and foot speed at impact in kicking a football with maximum effort. Sixteen Australian Rules (AR) footballers performed two different warm-ups on different days. One warm-up involved five minutes of sub-maximum running followed by seven practice kicks, while the other also included 4.5 minutes static stretching of the hip flexors and quadriceps after the running. A modified Thomas test was conduced before and after each warm-up. Players performed maximum effort drop punt kicks into a net while being videotaped to determine the ROM of the kicking leg and foot speed at impact with the ball. There were no significant changes in flexibility (p>0.05) as a result of either warm-up and there were no significant differences between the warm-ups in the kicking variables (p>0.05). It was concluded that the Thomas test may not have been sensitive to possible acute changes in flexibility from the warm-ups, and that stretching had no influence on kicking ROM or foot speed, possibly because of the complexity of the kicking skill.
- Description: C1
- Description: 2003000977
Acute effects of two massage techniques on ankle joint flexibility and power of the plantar flexors
- McKechnie, Grant, Young, Warren, Behm, David
- Authors: McKechnie, Grant , Young, Warren , Behm, David
- Date: 2007
- Type: Text , Journal article
- Relation: Journal of Sports Science and Medicine Vol. 6, no. 4 (2007), p. 498-504
- Full Text:
- Reviewed:
- Description: The purpose of this study was to determine if three minutes of petrissage and tapotement forms of massage would influence plantar flexors' flexibility, and muscle power. Nineteen participants were randomly subjected to three conditions (control and two massages) before performing two power tests. Prior to the intervention, subjects completed ankle joint flexibility assessments. The conditions were; (1) control, where subjects lay prone and had a therapist's hands resting, (2) vigorous petrissage, and (3) tapotement applied at a rate of 4Hz; all on the triceps surae. Following completion of the intervention, subjects immediately completed a post-ankle joint flexibility test, followed by a drop-jump and concentric calf raise. The power measures were; concentric peak force, rate of force development, and drop-jump height / contact time. The data showed a significant increase (p < 0.05) in ankle joint angle on the right leg and a corresponding tendency on the left. No significant change was seen with the power measures. Results suggest that massage can increase plantar flexors' flexibility without a change in power and thus may be an alternative to static stretching during an athletic warm-up. ©Journal of Sports Science and Medicine (2007).
- Description: C1
- Description: 2003005657
- Authors: McKechnie, Grant , Young, Warren , Behm, David
- Date: 2007
- Type: Text , Journal article
- Relation: Journal of Sports Science and Medicine Vol. 6, no. 4 (2007), p. 498-504
- Full Text:
- Reviewed:
- Description: The purpose of this study was to determine if three minutes of petrissage and tapotement forms of massage would influence plantar flexors' flexibility, and muscle power. Nineteen participants were randomly subjected to three conditions (control and two massages) before performing two power tests. Prior to the intervention, subjects completed ankle joint flexibility assessments. The conditions were; (1) control, where subjects lay prone and had a therapist's hands resting, (2) vigorous petrissage, and (3) tapotement applied at a rate of 4Hz; all on the triceps surae. Following completion of the intervention, subjects immediately completed a post-ankle joint flexibility test, followed by a drop-jump and concentric calf raise. The power measures were; concentric peak force, rate of force development, and drop-jump height / contact time. The data showed a significant increase (p < 0.05) in ankle joint angle on the right leg and a corresponding tendency on the left. No significant change was seen with the power measures. Results suggest that massage can increase plantar flexors' flexibility without a change in power and thus may be an alternative to static stretching during an athletic warm-up. ©Journal of Sports Science and Medicine (2007).
- Description: C1
- Description: 2003005657
Agility and change-of-direction speed are independent skills: Implications for training for agility in invasion sports
- Young, Warren, Dawson, Brian, Henry, Greg
- Authors: Young, Warren , Dawson, Brian , Henry, Greg
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Sports Science & Coaching Vol. 10, no. 1 (2015), p. 159-169
- Full Text:
- Reviewed:
- Description: This review explores the differences between agility in invasion sports (defined as including reactive decision-making) and change-of-direction speed (CODS), and highlights the implications for training. Correlations between agility tests and CODS tests indicate that they represent independent skills. Agility tests discriminate higher-from lower-standard athletes better than CODS tests, indicating that the cognitive element of agility is important to performance. Training studies have shown that the development of strength qualities can transfer to gains in CODS, but this has never been shown for agility. There is some evidence that the importance of physical qualities is greater for CODS than for agility. It was concluded that the reactive element should be included in agility training, testing and research. While there appears to be no research evidence for the benefits of strength and power training, there is some support for the use of small-sided games for improving agility.
- Authors: Young, Warren , Dawson, Brian , Henry, Greg
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Sports Science & Coaching Vol. 10, no. 1 (2015), p. 159-169
- Full Text:
- Reviewed:
- Description: This review explores the differences between agility in invasion sports (defined as including reactive decision-making) and change-of-direction speed (CODS), and highlights the implications for training. Correlations between agility tests and CODS tests indicate that they represent independent skills. Agility tests discriminate higher-from lower-standard athletes better than CODS tests, indicating that the cognitive element of agility is important to performance. Training studies have shown that the development of strength qualities can transfer to gains in CODS, but this has never been shown for agility. There is some evidence that the importance of physical qualities is greater for CODS than for agility. It was concluded that the reactive element should be included in agility training, testing and research. While there appears to be no research evidence for the benefits of strength and power training, there is some support for the use of small-sided games for improving agility.
Agility literature review : Classifications, training and testing
- Sheppard, Jeremy, Young, Warren
- Authors: Sheppard, Jeremy , Young, Warren
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 24, no. 9 (Sep 2006), p. 919-932
- Full Text:
- Reviewed:
- Description: At present, no agreement on a precise definition of agility within the sports science community exists. The term is applied to a broad range of sport contexts, but with such great inconsistency, it further complicates our understanding of what trainable components may enhance agility. A new definition of agility is proposed: "a rapid whole-body movement with change of velocity or direction in response to a stimulus". Agility has relationships with trainable physical qualities such as strength, power and technique, as well as cognitive components such as visual-scanning techniques, visual-scanning speed and anticipation. Agility testing is generally confined to tests of physical components such as change of direction speed, or cognitive components such as anticipation and pattern recognition. New tests of agility that combine physical and cognitive measures are encouraged.
- Description: C1
- Description: 2003002129
- Authors: Sheppard, Jeremy , Young, Warren
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 24, no. 9 (Sep 2006), p. 919-932
- Full Text:
- Reviewed:
- Description: At present, no agreement on a precise definition of agility within the sports science community exists. The term is applied to a broad range of sport contexts, but with such great inconsistency, it further complicates our understanding of what trainable components may enhance agility. A new definition of agility is proposed: "a rapid whole-body movement with change of velocity or direction in response to a stimulus". Agility has relationships with trainable physical qualities such as strength, power and technique, as well as cognitive components such as visual-scanning techniques, visual-scanning speed and anticipation. Agility testing is generally confined to tests of physical components such as change of direction speed, or cognitive components such as anticipation and pattern recognition. New tests of agility that combine physical and cognitive measures are encouraged.
- Description: C1
- Description: 2003002129
An evaluation of a new test of reactive agility and its relationship to sprint speed and change of direction speed
- Sheppard, Jeremy, Young, Warren, Doyle, Tim, Sheppard, T. A., Newton, Robert
- Authors: Sheppard, Jeremy , Young, Warren , Doyle, Tim , Sheppard, T. A. , Newton, Robert
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 9, no. 4 (2006), p. 342-349
- Full Text:
- Reviewed:
- Description: The purpose of this study was to evaluate the reliability and validity of a new test of agility, the reactive agility test (RAT), which included anticipation and decision-making components in response to the movements of a tester. Thirty-eight Australian football players took part in the study, categorized into either a higher performance group (HPG) (n = 24) or lower performance group (LPG) (n = 14) based on playing level from the previous season. All participants undertook testing of a 10 m straight sprint (10 mSS), a 8-9 m change of direction speed test (CODST), and the RAT. Test-retest and inter-tester reliability testing measures were conducted with the LPG. The intra-class correlation (ICC) of the RAT was 0.870, with no significant (p < 0.05) difference between the test results obtained on the first and second test sessions using a t-test. A dependent samples t-test revealed no significant (p < 0.05) difference between the test results of two different testers with the same population. The HPG were significantly (p = 0.001) superior to those of the LPG on the RAT, with no differences observed on any other variable. The RAT is an acceptably reliable test when considering both test-retest reliability, as well as inter-rater reliability. In addition, the test was valid in distinguishing between players of differing performance level in Australian football, while the 10 mSS and CODST were not. This result suggests that traditional closed skill sprint and sprint with direction change tests may not adequately distinguish between players of different levels of competition in Australian football. © 2006 Sports Medicine Australia.
- Description: C1
- Description: 2003002132
- Authors: Sheppard, Jeremy , Young, Warren , Doyle, Tim , Sheppard, T. A. , Newton, Robert
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 9, no. 4 (2006), p. 342-349
- Full Text:
- Reviewed:
- Description: The purpose of this study was to evaluate the reliability and validity of a new test of agility, the reactive agility test (RAT), which included anticipation and decision-making components in response to the movements of a tester. Thirty-eight Australian football players took part in the study, categorized into either a higher performance group (HPG) (n = 24) or lower performance group (LPG) (n = 14) based on playing level from the previous season. All participants undertook testing of a 10 m straight sprint (10 mSS), a 8-9 m change of direction speed test (CODST), and the RAT. Test-retest and inter-tester reliability testing measures were conducted with the LPG. The intra-class correlation (ICC) of the RAT was 0.870, with no significant (p < 0.05) difference between the test results obtained on the first and second test sessions using a t-test. A dependent samples t-test revealed no significant (p < 0.05) difference between the test results of two different testers with the same population. The HPG were significantly (p = 0.001) superior to those of the LPG on the RAT, with no differences observed on any other variable. The RAT is an acceptably reliable test when considering both test-retest reliability, as well as inter-rater reliability. In addition, the test was valid in distinguishing between players of differing performance level in Australian football, while the 10 mSS and CODST were not. This result suggests that traditional closed skill sprint and sprint with direction change tests may not adequately distinguish between players of different levels of competition in Australian football. © 2006 Sports Medicine Australia.
- Description: C1
- Description: 2003002132
Analysis of a reactive agility field test
- Authors: Young, Warren , Willey, Ben
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 13, no. 3 (2010), p. 376-378
- Full Text:
- Reviewed:
- Description: The purpose of this research was to evaluate a reactive agility test by determining the relationships between the total time recorded for the test and various components. A tester used side-step movements to provide a stimulus for the athlete to change direction. By using electronic timing and high speed video analysis of the test, three times were recorded. These were the time taken for the tester to display the stimulus to change direction (tester time), the time taken by the participant to respond to the stimulus (decision time), and the time taken by the participant to change direction and sprint to the left or right (response movement time). Thirty-one semi-professional Australian Rules football players were assessed by analysing the mean of eight trials of the reactive agility test. The greatest correlation with total time was r = 0.77 for decision time (p = 0.00), with movement time and tester time producing coefficients of 0.59 (p = 0.00) and 0.37 (p = 0.04), respectively. The coefficient of variation for the mean tester time was 5.1%. It was concluded that perceptual skill as measured by decision time is an important component of the reactive agility test and the tester time should be controlled by using high speed video recordings to isolate its influence. © 2009 Sports Medicine Australia.
- Authors: Young, Warren , Willey, Ben
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 13, no. 3 (2010), p. 376-378
- Full Text:
- Reviewed:
- Description: The purpose of this research was to evaluate a reactive agility test by determining the relationships between the total time recorded for the test and various components. A tester used side-step movements to provide a stimulus for the athlete to change direction. By using electronic timing and high speed video analysis of the test, three times were recorded. These were the time taken for the tester to display the stimulus to change direction (tester time), the time taken by the participant to respond to the stimulus (decision time), and the time taken by the participant to change direction and sprint to the left or right (response movement time). Thirty-one semi-professional Australian Rules football players were assessed by analysing the mean of eight trials of the reactive agility test. The greatest correlation with total time was r = 0.77 for decision time (p = 0.00), with movement time and tester time producing coefficients of 0.59 (p = 0.00) and 0.37 (p = 0.04), respectively. The coefficient of variation for the mean tester time was 5.1%. It was concluded that perceptual skill as measured by decision time is an important component of the reactive agility test and the tester time should be controlled by using high speed video recordings to isolate its influence. © 2009 Sports Medicine Australia.
Association between leg power and sprinting technique with 20-m sprint performance in elite junior australian football players
- Young, Warren, Grace, Steve, Talpey, Scott
- Authors: Young, Warren , Grace, Steve , Talpey, Scott
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 9, no. 5 (2014), p. 1153-1160
- Full Text:
- Reviewed:
- Description: The main purpose of this study was to determine the association between leg power and sprint technique with 20-m sprint performance. Seventy-seven elite junior Australian Rules football players were assessed on a 20-m sprint test, a countermovement jump (CMJ) and a two bound test, and on a new method of quantifying sprint technique from simple video recordings. Technique assessment involved rating 14 points on a scale from 1-5. Players were median-split into faster and slower groups based on their 20-m times, and they were compared for differences in leg power and technique. The faster group was significantly better (p<0.05) in the two-bound test (5.2%) and the technique score (8.2%), but not in the CMJ (p>0.05). A multiple regression indicated that the two-bound test and technique accounted for 37.7% of the variance associated with the 20-m sprint time (p<0.05). It was concluded that the technique assessment tool captured some important characteristics of 20-m sprint performance and could potentially be used to profile or monitor athletes. Further the two-bound test is a more relevant test for developing athletes because of its specificity to sprinting, compared to the CMJ.
- Authors: Young, Warren , Grace, Steve , Talpey, Scott
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 9, no. 5 (2014), p. 1153-1160
- Full Text:
- Reviewed:
- Description: The main purpose of this study was to determine the association between leg power and sprint technique with 20-m sprint performance. Seventy-seven elite junior Australian Rules football players were assessed on a 20-m sprint test, a countermovement jump (CMJ) and a two bound test, and on a new method of quantifying sprint technique from simple video recordings. Technique assessment involved rating 14 points on a scale from 1-5. Players were median-split into faster and slower groups based on their 20-m times, and they were compared for differences in leg power and technique. The faster group was significantly better (p<0.05) in the two-bound test (5.2%) and the technique score (8.2%), but not in the CMJ (p>0.05). A multiple regression indicated that the two-bound test and technique accounted for 37.7% of the variance associated with the 20-m sprint time (p<0.05). It was concluded that the technique assessment tool captured some important characteristics of 20-m sprint performance and could potentially be used to profile or monitor athletes. Further the two-bound test is a more relevant test for developing athletes because of its specificity to sprinting, compared to the CMJ.
Association between preseason training and performance in elite Australian football
- McCaskie, Callum, Young, Warren, Fahrner, Brendan, Sim, Marc
- Authors: McCaskie, Callum , Young, Warren , Fahrner, Brendan , Sim, Marc
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 14, no. 1 (2019), p. 68-75
- Full Text:
- Reviewed:
- Description: Purpose: To examine the association between preseason training variables and subsequent in-season performance in an elite Australian football team. Methods: Data from 41 elite male Australian footballers (mean [SD] age = 23.4 [3.1] y, height =188.4 [7.1] cm, and mass = 86.7 [7.9] kg) were collected from 1 Australian Football League (AFL) club. Preseason training data (external load, internal load, fitness testing, and session participation) were collected across the 17-wk preseason phase (6 and 11 wk post-Christmas). Champion Data© Player Rank (CDPR), coaches’ ratings, and round 1 selection were used as in-season performance measures. CDPR and coaches’ ratings were examined over the entire season, first half of the season, and the first 4 games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between preseason training variables and in-season performance measures. A median split was also employed to differentiate between higher- and lower-performing players for each performance measure. Results: Preseason training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many preseason training variables were significantly linked with performance measured across the first 4 games. Preseason training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, total on-field session rating of perceived exertion post-Christmas, a measurement of internal load, displayed the greatest association with performance. Conclusion: Late preseason training (especially on-field match-specific training) is associated with better performance in the early season.
- Authors: McCaskie, Callum , Young, Warren , Fahrner, Brendan , Sim, Marc
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 14, no. 1 (2019), p. 68-75
- Full Text:
- Reviewed:
- Description: Purpose: To examine the association between preseason training variables and subsequent in-season performance in an elite Australian football team. Methods: Data from 41 elite male Australian footballers (mean [SD] age = 23.4 [3.1] y, height =188.4 [7.1] cm, and mass = 86.7 [7.9] kg) were collected from 1 Australian Football League (AFL) club. Preseason training data (external load, internal load, fitness testing, and session participation) were collected across the 17-wk preseason phase (6 and 11 wk post-Christmas). Champion Data© Player Rank (CDPR), coaches’ ratings, and round 1 selection were used as in-season performance measures. CDPR and coaches’ ratings were examined over the entire season, first half of the season, and the first 4 games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between preseason training variables and in-season performance measures. A median split was also employed to differentiate between higher- and lower-performing players for each performance measure. Results: Preseason training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many preseason training variables were significantly linked with performance measured across the first 4 games. Preseason training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, total on-field session rating of perceived exertion post-Christmas, a measurement of internal load, displayed the greatest association with performance. Conclusion: Late preseason training (especially on-field match-specific training) is associated with better performance in the early season.
Caffeine, carbohydrate, and cooling use during prolonged simulated tennis
- Hornery, Daniel, Mujika, Inigo, Young, Warren, Farrow, Damian
- Authors: Hornery, Daniel , Mujika, Inigo , Young, Warren , Farrow, Damian
- Date: 2007
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 2, no. 4 (2007), p. 423-438
- Full Text:
- Reviewed:
- Description: Purpose: To determine the effects of prolonged simulated tennis on performance and the ergogenic potential of caffeine, carbohydrates, and cooling. Methods: Twelve highly trained male tennis players (age 18.3 ± 3.0 y, height 178.8 ± 8.5 cm, body mass 73.95 ± 12.30 kg, mean ± SD) performed 4 simulated matches (2 h 40 min) against a ball machine on an indoor hard court. The counterbalanced experimental trials involved caffeine supplementation (3 mg/kg), carbohydrate supplementation (6% solution), precooling and intermittent cooling, and placebo control. Physiological markers (core temperature, heart rate, blood lactate, and blood glucose), subjective responses (ratings of perceived exertion and thermal sensation), stroke velocity and accuracy, serve kinematics, and tennis-specific perceptual skill quantified the efficacy of interventions. Results: Significant effects of time (P < .01) reflected increased physiological demand, reduced serve velocity and ground-stroke velocity and accuracy, and a slowing of the serve racket-arm acceleration phase. Caffeine increased serve velocity (165 ± 15 km/h) in the final set of the match (P = .014) compared with placebo (159 ± 15 km/h, P = .008) and carbohydrate (158 ± 13 km/h, P = .001) conditions. Carbohydrate and cooling conditions afforded physiological advantage (increased blood glucose, P < .01, and reduced preexercise thermal sensation, P < .01) but did not affect performance relative to the placebo condition. Conclusions: Prolonged simulated tennis induced significant decrements in tennis skills. Caffeine supplementation partly attenuated the effects of fatigue and increased serve velocity. In contrast, carbohydrate and cooling strategies had little ergogenic effect on tennis performance.
- Description: C1
- Description: 2003005648
- Authors: Hornery, Daniel , Mujika, Inigo , Young, Warren , Farrow, Damian
- Date: 2007
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 2, no. 4 (2007), p. 423-438
- Full Text:
- Reviewed:
- Description: Purpose: To determine the effects of prolonged simulated tennis on performance and the ergogenic potential of caffeine, carbohydrates, and cooling. Methods: Twelve highly trained male tennis players (age 18.3 ± 3.0 y, height 178.8 ± 8.5 cm, body mass 73.95 ± 12.30 kg, mean ± SD) performed 4 simulated matches (2 h 40 min) against a ball machine on an indoor hard court. The counterbalanced experimental trials involved caffeine supplementation (3 mg/kg), carbohydrate supplementation (6% solution), precooling and intermittent cooling, and placebo control. Physiological markers (core temperature, heart rate, blood lactate, and blood glucose), subjective responses (ratings of perceived exertion and thermal sensation), stroke velocity and accuracy, serve kinematics, and tennis-specific perceptual skill quantified the efficacy of interventions. Results: Significant effects of time (P < .01) reflected increased physiological demand, reduced serve velocity and ground-stroke velocity and accuracy, and a slowing of the serve racket-arm acceleration phase. Caffeine increased serve velocity (165 ± 15 km/h) in the final set of the match (P = .014) compared with placebo (159 ± 15 km/h, P = .008) and carbohydrate (158 ± 13 km/h, P = .001) conditions. Carbohydrate and cooling conditions afforded physiological advantage (increased blood glucose, P < .01, and reduced preexercise thermal sensation, P < .01) but did not affect performance relative to the placebo condition. Conclusions: Prolonged simulated tennis induced significant decrements in tennis skills. Caffeine supplementation partly attenuated the effects of fatigue and increased serve velocity. In contrast, carbohydrate and cooling strategies had little ergogenic effect on tennis performance.
- Description: C1
- Description: 2003005648
Comparison of agility demands of small-sided games in elite Australian football
- Davies, Michael, Young, Warren, Farrow, Damian, Bahnert, Andrew
- Authors: Davies, Michael , Young, Warren , Farrow, Damian , Bahnert, Andrew
- Date: 2013
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 8, no. 2 (2013), p. 139-147
- Full Text:
- Reviewed:
- Description: Purpose: To compare the agility demands of 4 small-sided games (SSGs) and evaluate the variability in demands for elite Australian Football (AF). Methods: Fourteen male elite Australian Football League (AFL) players (mean ± SD; 21.7 ± 3.1 y, 189.6 ± 9.0 cm, 88.7 ± 10.0 kg, 39.4 ± 57.1 games) completed 4 SSGs of 3 x 45-s bouts each with modified designs. Video notational analysis, GPS at 5 Hz, and triaxial accelerometer data expressed the external player loads within games. Three comparisons were made using a paired t test (P < .05), and magnitudes of differences were reported with effect size (ES) statistics. Results: Reduced area per player (increased density) produced a small increase in total agility maneuvers (SSG1, 7.2 ± 1.3; SSG2, 8.8 ± 4.1), while a large 2D player load was accumulated (P < .05, ES = 1.22). A reduction in players produced a moderate (ES = 0.60) total number of agility maneuvers (SSG 3, 11.3 ± 6.1; SSG 2, 8.3 ± 3.6); however, a greater variability was found. The implementation of a 2-handed-tag rule resulted in a somewhat trivial decline (P > .05, ES = 0.16) in agility events compared with normal AFL tackling rules (SSG 2, 8.3 ± 3.6; SSG 4, 7.8 ± 2.6). Conclusions: SSG characteristics can influence agility-training demand, which can vary considerably for individuals. Coaches should carefully consider SSG design to maximize the potential to develop agility for all players. © 2013 Human Kinetics, Inc.
- Description: 2003010585
- Authors: Davies, Michael , Young, Warren , Farrow, Damian , Bahnert, Andrew
- Date: 2013
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 8, no. 2 (2013), p. 139-147
- Full Text:
- Reviewed:
- Description: Purpose: To compare the agility demands of 4 small-sided games (SSGs) and evaluate the variability in demands for elite Australian Football (AF). Methods: Fourteen male elite Australian Football League (AFL) players (mean ± SD; 21.7 ± 3.1 y, 189.6 ± 9.0 cm, 88.7 ± 10.0 kg, 39.4 ± 57.1 games) completed 4 SSGs of 3 x 45-s bouts each with modified designs. Video notational analysis, GPS at 5 Hz, and triaxial accelerometer data expressed the external player loads within games. Three comparisons were made using a paired t test (P < .05), and magnitudes of differences were reported with effect size (ES) statistics. Results: Reduced area per player (increased density) produced a small increase in total agility maneuvers (SSG1, 7.2 ± 1.3; SSG2, 8.8 ± 4.1), while a large 2D player load was accumulated (P < .05, ES = 1.22). A reduction in players produced a moderate (ES = 0.60) total number of agility maneuvers (SSG 3, 11.3 ± 6.1; SSG 2, 8.3 ± 3.6); however, a greater variability was found. The implementation of a 2-handed-tag rule resulted in a somewhat trivial decline (P > .05, ES = 0.16) in agility events compared with normal AFL tackling rules (SSG 2, 8.3 ± 3.6; SSG 4, 7.8 ± 2.6). Conclusions: SSG characteristics can influence agility-training demand, which can vary considerably for individuals. Coaches should carefully consider SSG design to maximize the potential to develop agility for all players. © 2013 Human Kinetics, Inc.
- Description: 2003010585
Comparison of physical activity in small-sided basketball games versus full-sided games
- McCormick, Brian, Hannon, James, Newton, Maria, Shultz, Barry, Miller, Nicole, Young, Warren
- Authors: McCormick, Brian , Hannon, James , Newton, Maria , Shultz, Barry , Miller, Nicole , Young, Warren
- Date: 2012
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 7, no. 4 (2012), p. 689-697
- Full Text:
- Reviewed:
- Description: Organized youth sports leagues attempt to meet many goals. Three primary needs for a youth sports league are to meet the participants' desires, provide quality learning experiences, and develop the competencies needed for continued participation. Possessing the ball, shooting more, and being more involved with a team's offense lead to more enjoyment and feelings of competence. Therefore, increasing the involvement of each player through more ball contacts should be a goal of youth sports leagues. Twelve male basketball players (age=15) from one high-school basketball team participated in this study. This study used paired t-tests to examine the differences between three-on-three basketball games and five-on-five basketball games that lasted for eight minutes in terms of average heart rate, moderate to vigorous intensity physical activity, vigorous intensity activity, and ball contacts. There were no significant differences between average heart rate, moderate-to-vigorous intensity activity, or vigorous intensity activity in the two conditions, but there were significantly more ball contacts on average in the three-on-three games. These results suggest that three-on-three leagues may be an appropriate sport for the initial exposure to basketball for youth players.
- Description: 2003010574
- Authors: McCormick, Brian , Hannon, James , Newton, Maria , Shultz, Barry , Miller, Nicole , Young, Warren
- Date: 2012
- Type: Text , Journal article
- Relation: International Journal of Sports Science and Coaching Vol. 7, no. 4 (2012), p. 689-697
- Full Text:
- Reviewed:
- Description: Organized youth sports leagues attempt to meet many goals. Three primary needs for a youth sports league are to meet the participants' desires, provide quality learning experiences, and develop the competencies needed for continued participation. Possessing the ball, shooting more, and being more involved with a team's offense lead to more enjoyment and feelings of competence. Therefore, increasing the involvement of each player through more ball contacts should be a goal of youth sports leagues. Twelve male basketball players (age=15) from one high-school basketball team participated in this study. This study used paired t-tests to examine the differences between three-on-three basketball games and five-on-five basketball games that lasted for eight minutes in terms of average heart rate, moderate to vigorous intensity physical activity, vigorous intensity activity, and ball contacts. There were no significant differences between average heart rate, moderate-to-vigorous intensity activity, or vigorous intensity activity in the two conditions, but there were significantly more ball contacts on average in the three-on-three games. These results suggest that three-on-three leagues may be an appropriate sport for the initial exposure to basketball for youth players.
- Description: 2003010574
Conflicting effects of fatigue and potentiation on voluntary force
- Behm, David, Button, Duane, Barbour, Glen, Butt, Jeremy, Young, Warren
- Authors: Behm, David , Button, Duane , Barbour, Glen , Butt, Jeremy , Young, Warren
- Date: 2004
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 18, no. 2 (2004), p. 365-372
- Full Text:
- Reviewed:
- Description: The objective of this study was to investigate whether a warm-up consisting of a series of maximal contractions would augment the force and activation of subsequent leg extensor contractions. Both voluntary and evoked isometric contractions were tested to determine the mechanisms underlying the response. Nine subjects were tested for twitch, tetanic, submaximal (30%), and maximal voluntary contractile (MVC) properties before and after (1, 5, 10, and 15 minutes) one to three 10-second MVCs. MVC force either did not change following 1-2 MVCs or was depressed at 10 and 15 minutes after 3 MVCs. MVC activation was decreased (4.4-6.9%) throughout recovery, whereas submaximal contractions were minimally affected. Although overall, twitches were potentiated (15.5-19.8%) posttest, 3 MVCs had significantly greater twitch potentiation than 1 or 2 MVCs at 5 and 10 minutes. Results suggest that voluntary and evoked contractions respond differently to prior 10-second MVCs. In the present study, a warm-up routine of 1-3 MVCs of a 10-second duration did not enhance subsequent voluntary performance.
- Description: C1
- Description: 2003001186
- Authors: Behm, David , Button, Duane , Barbour, Glen , Butt, Jeremy , Young, Warren
- Date: 2004
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 18, no. 2 (2004), p. 365-372
- Full Text:
- Reviewed:
- Description: The objective of this study was to investigate whether a warm-up consisting of a series of maximal contractions would augment the force and activation of subsequent leg extensor contractions. Both voluntary and evoked isometric contractions were tested to determine the mechanisms underlying the response. Nine subjects were tested for twitch, tetanic, submaximal (30%), and maximal voluntary contractile (MVC) properties before and after (1, 5, 10, and 15 minutes) one to three 10-second MVCs. MVC force either did not change following 1-2 MVCs or was depressed at 10 and 15 minutes after 3 MVCs. MVC activation was decreased (4.4-6.9%) throughout recovery, whereas submaximal contractions were minimally affected. Although overall, twitches were potentiated (15.5-19.8%) posttest, 3 MVCs had significantly greater twitch potentiation than 1 or 2 MVCs at 5 and 10 minutes. Results suggest that voluntary and evoked contractions respond differently to prior 10-second MVCs. In the present study, a warm-up routine of 1-3 MVCs of a 10-second duration did not enhance subsequent voluntary performance.
- Description: C1
- Description: 2003001186
Countermovement jump variables not tensiomyography can distinguish between sprint and endurance focused track cyclists
- Lewis, Mitchell, Young, Warren, Knapstein, Luke, Lavender, Andrew, Talpey, Scott
- Authors: Lewis, Mitchell , Young, Warren , Knapstein, Luke , Lavender, Andrew , Talpey, Scott
- Date: 2022
- Type: Text , Journal article
- Relation: Biology of Sport Vol. 39, no. 1 (2022), p. 67-72
- Full Text:
- Reviewed:
- Description: This study investigated the reliability and discriminative ability of tensiomyography and countermovement jump variables as measures of a muscles contractile properties in a cohort of elite endurance and sprint track cyclists. Tensiomyography was performed on the vastus lateralis (VL) and rectus femoris (RF) muscles in sprint track cyclists (N = 8) and endurance track cyclists (N = 8). Additionally, the participants completed a countermovement jump on a force plate. Tensiomyography measurements obtained from the RF displayed greater reliability (ICC = 0.879–0.997) than VL (ICC = 0.746–0.970). Radial muscle belly displacement (Dm), contraction time (Tc) and delay time (Td) demonstrated the most reliable TMG measurements. Only two variables displayed acceptable coefficient of variation (RF Td = 8.89, VL Td = 6.88), other variables presented as unacceptable. The TMG variables were unable to discriminate between endurance and sprint track cyclists whilst the CMJ variables could. Due to the high variability in measurements and its inability to distinguish between sprint and endurance based track cyclists TMG should be used cautiously in this athlete population and if available the CMJ is a more appropriate assessment of leg muscle function. © 2022 Institute of Sport. All rights reserved.
- Authors: Lewis, Mitchell , Young, Warren , Knapstein, Luke , Lavender, Andrew , Talpey, Scott
- Date: 2022
- Type: Text , Journal article
- Relation: Biology of Sport Vol. 39, no. 1 (2022), p. 67-72
- Full Text:
- Reviewed:
- Description: This study investigated the reliability and discriminative ability of tensiomyography and countermovement jump variables as measures of a muscles contractile properties in a cohort of elite endurance and sprint track cyclists. Tensiomyography was performed on the vastus lateralis (VL) and rectus femoris (RF) muscles in sprint track cyclists (N = 8) and endurance track cyclists (N = 8). Additionally, the participants completed a countermovement jump on a force plate. Tensiomyography measurements obtained from the RF displayed greater reliability (ICC = 0.879–0.997) than VL (ICC = 0.746–0.970). Radial muscle belly displacement (Dm), contraction time (Tc) and delay time (Td) demonstrated the most reliable TMG measurements. Only two variables displayed acceptable coefficient of variation (RF Td = 8.89, VL Td = 6.88), other variables presented as unacceptable. The TMG variables were unable to discriminate between endurance and sprint track cyclists whilst the CMJ variables could. Due to the high variability in measurements and its inability to distinguish between sprint and endurance based track cyclists TMG should be used cautiously in this athlete population and if available the CMJ is a more appropriate assessment of leg muscle function. © 2022 Institute of Sport. All rights reserved.
Development of muscle mass : How much is optimum for performance?
- Young, Warren, Talpey, Scott, Bartlett, Rogan, Lewis, Mitchell, Mundy, Stephanie, Smyth, Andrew, Welsh, Tim
- Authors: Young, Warren , Talpey, Scott , Bartlett, Rogan , Lewis, Mitchell , Mundy, Stephanie , Smyth, Andrew , Welsh, Tim
- Date: 2019
- Type: Text , Journal article
- Relation: Strength and Conditioning Journal Vol. 41, no. 3 (2019), p. 47-50
- Full Text:
- Reviewed:
- Description: Training for muscle hypertrophy can be expected to induce some increase in total body mass, and this can have positive or negative consequences for athletic performance. Positive effects may be increased strength, increased resistance to being pushed aside, and greater momentum when running, whereas possible negative effects may be reduced capacity to accelerate, decelerate, change direction, and jump. These possible effects of gaining muscle and total body mass suggest that strength and conditioning coaches should give thoughtful consideration to the amount of hypertrophy training prescribed throughout an athletes's development and should be determined by the specific needs of the athlete.
- Description: TRAINING FOR MUSCLE HYPERTROPHY CAN BE EXPECTED TO INDUCE SOME INCREASE IN TOTAL BODY MASS, AND THIS CAN HAVE POSITIVE OR NEGATIVE CONSEQUENCES FOR ATHLETIC PERFORMANCE. POSITIVE EFFECTS MAY BE INCREASED STRENGTH, INCREASED RESISTANCE TO BEING PUSHED ASIDE, AND GREATER MOMENTUM WHEN RUNNING, WHEREAS POSSIBLE NEGATIVE EFFECTS MAY BE REDUCED CAPACITY TO ACCELERATE, DECELERATE, CHANGE DIRECTION, AND JUMP. THESE POSSIBLE EFFECTS OF GAINING MUSCLE AND TOTAL BODY MASS SUGGEST THAT STRENGTH AND CONDITIONING COACHES SHOULD GIVE THOUGHTFUL CONSIDERATION TO THE AMOUNT OF HYPERTROPHY TRAINING PRESCRIBED THROUGHOUT AN ATHLETE'S DEVELOPMENT AND SHOULD BE DETERMINED BY THE SPECIFIC NEEDS OF THE ATHLETE.
- Authors: Young, Warren , Talpey, Scott , Bartlett, Rogan , Lewis, Mitchell , Mundy, Stephanie , Smyth, Andrew , Welsh, Tim
- Date: 2019
- Type: Text , Journal article
- Relation: Strength and Conditioning Journal Vol. 41, no. 3 (2019), p. 47-50
- Full Text:
- Reviewed:
- Description: Training for muscle hypertrophy can be expected to induce some increase in total body mass, and this can have positive or negative consequences for athletic performance. Positive effects may be increased strength, increased resistance to being pushed aside, and greater momentum when running, whereas possible negative effects may be reduced capacity to accelerate, decelerate, change direction, and jump. These possible effects of gaining muscle and total body mass suggest that strength and conditioning coaches should give thoughtful consideration to the amount of hypertrophy training prescribed throughout an athletes's development and should be determined by the specific needs of the athlete.
- Description: TRAINING FOR MUSCLE HYPERTROPHY CAN BE EXPECTED TO INDUCE SOME INCREASE IN TOTAL BODY MASS, AND THIS CAN HAVE POSITIVE OR NEGATIVE CONSEQUENCES FOR ATHLETIC PERFORMANCE. POSITIVE EFFECTS MAY BE INCREASED STRENGTH, INCREASED RESISTANCE TO BEING PUSHED ASIDE, AND GREATER MOMENTUM WHEN RUNNING, WHEREAS POSSIBLE NEGATIVE EFFECTS MAY BE REDUCED CAPACITY TO ACCELERATE, DECELERATE, CHANGE DIRECTION, AND JUMP. THESE POSSIBLE EFFECTS OF GAINING MUSCLE AND TOTAL BODY MASS SUGGEST THAT STRENGTH AND CONDITIONING COACHES SHOULD GIVE THOUGHTFUL CONSIDERATION TO THE AMOUNT OF HYPERTROPHY TRAINING PRESCRIBED THROUGHOUT AN ATHLETE'S DEVELOPMENT AND SHOULD BE DETERMINED BY THE SPECIFIC NEEDS OF THE ATHLETE.
Does the warm-up effect subsequent post activation performance enhancement?
- O'Grady, Mathew, Young, Warren, Talpey, Scott, Behm, David
- Authors: O'Grady, Mathew , Young, Warren , Talpey, Scott , Behm, David
- Date: 2021
- Type: Text , Journal article
- Relation: The Journal of Sport and Exercise Science Vol. 5, no. 4 (SESN 2021), p.
- Full Text:
- Reviewed:
- Description: The purpose of the following study was first to identify an optimal warm-up to maximise countermovement jump (CMJ) performance, and second to investigate whether a conditioning activity (CA) of half-squats could potentiate CMJ performance above that of the optimal warm-up. Sixteen resistance trained males were recruited for the study. Participants performed six different warm-up volumes over six sessions. Warm-ups consisted of submaximal running, dynamic stretching and practice CMJs. After the warmup, participants rested for four minutes before performing three CMJs on a force platform. The warm-up which resulted in the best CMJ relative peak power (RPP) was considered to be that individual’s optimal warm-up. Participants attended another testing session where they performed their optimum warm-up followed by a pre-CMJ test. Participants then performed a CA of four half-squats with a 5RM load followed by post-CMJ tests after fourand eight-minutes recovery. No CMJ variable displayed significant improvements at either four or eight minutes recovery after the CA when compared to the pre-test. However, when everyone’s optimum recovery period was considered, CMJ height significantly improved by 5.2% (p = 0.009) when compared with pre-CMJ performance. If the optimum recovery period is considered, a half-squat CA can further mprove CMJ height above that of a general warm-up alone
- Authors: O'Grady, Mathew , Young, Warren , Talpey, Scott , Behm, David
- Date: 2021
- Type: Text , Journal article
- Relation: The Journal of Sport and Exercise Science Vol. 5, no. 4 (SESN 2021), p.
- Full Text:
- Reviewed:
- Description: The purpose of the following study was first to identify an optimal warm-up to maximise countermovement jump (CMJ) performance, and second to investigate whether a conditioning activity (CA) of half-squats could potentiate CMJ performance above that of the optimal warm-up. Sixteen resistance trained males were recruited for the study. Participants performed six different warm-up volumes over six sessions. Warm-ups consisted of submaximal running, dynamic stretching and practice CMJs. After the warmup, participants rested for four minutes before performing three CMJs on a force platform. The warm-up which resulted in the best CMJ relative peak power (RPP) was considered to be that individual’s optimal warm-up. Participants attended another testing session where they performed their optimum warm-up followed by a pre-CMJ test. Participants then performed a CA of four half-squats with a 5RM load followed by post-CMJ tests after fourand eight-minutes recovery. No CMJ variable displayed significant improvements at either four or eight minutes recovery after the CA when compared to the pre-test. However, when everyone’s optimum recovery period was considered, CMJ height significantly improved by 5.2% (p = 0.009) when compared with pre-CMJ performance. If the optimum recovery period is considered, a half-squat CA can further mprove CMJ height above that of a general warm-up alone
Fixed foot balance training increases rectus femoris activation during landing and jump height in recreationally active women
- Kean, Crystal, Behm, David, Young, Warren
- Authors: Kean, Crystal , Behm, David , Young, Warren
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Sports Science and Medicine Vol. 5, no. 1 (2006), p. 138-148
- Full Text:
- Reviewed:
- Description: The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally active females were tested pre- and post-training (fixed foot balance training, n= 11, functionally directed balance training, n = 7 and control group, n = 6). Experimental subjects completed either fixed foot or functionally directed balance exercises 4 times/week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings following a jump. Maximum vertical jump height, static balance and 20-meter sprint times were also examined. The fixed foot balance-training group showed a 33% improvement (p < 0.05) in static balance time and 9% improvement in jump height. Neither type of training improved sprint times. Further analysis revealed significant (p < 0.05) overall (data collapsed over groups and legs) increases in reactive RF activity when landing. Independently, the fixed foot balance group showed a 33% increase in reactive RF activity (p < 0.01). Overall, there was also significantly less reactive co-activation following training (p < 0.05). It appears that fixed foot balance training for recreationally active women may provide greater RF activity when landing and increased countermovement jump height. ©Journal of Sports Science and Medicine (2006).
- Description: C1
- Description: 2003002123
- Authors: Kean, Crystal , Behm, David , Young, Warren
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Sports Science and Medicine Vol. 5, no. 1 (2006), p. 138-148
- Full Text:
- Reviewed:
- Description: The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally active females were tested pre- and post-training (fixed foot balance training, n= 11, functionally directed balance training, n = 7 and control group, n = 6). Experimental subjects completed either fixed foot or functionally directed balance exercises 4 times/week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings following a jump. Maximum vertical jump height, static balance and 20-meter sprint times were also examined. The fixed foot balance-training group showed a 33% improvement (p < 0.05) in static balance time and 9% improvement in jump height. Neither type of training improved sprint times. Further analysis revealed significant (p < 0.05) overall (data collapsed over groups and legs) increases in reactive RF activity when landing. Independently, the fixed foot balance group showed a 33% increase in reactive RF activity (p < 0.01). Overall, there was also significantly less reactive co-activation following training (p < 0.05). It appears that fixed foot balance training for recreationally active women may provide greater RF activity when landing and increased countermovement jump height. ©Journal of Sports Science and Medicine (2006).
- Description: C1
- Description: 2003002123
Movement demands in Australian Rules football as indicators of muscle damage
- Young, Warren, Hepner, Jamie, Robbins, Daniel
- Authors: Young, Warren , Hepner, Jamie , Robbins, Daniel
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 26, no. 2 (2012), p. 492-496
- Full Text:
- Reviewed:
- Description: The purpose of this study was to determine if there is an association between variables that describe movements in an Australian Rules football (ARF) game with muscle damage. Fourteen elite junior ARF players were monitored with a global positioning system (GPS) during a match, and muscle damage was estimated by determining creatine kinase (CK) 24 hours postmatch. The players were median split based on CK levels, into a high and low CK group, and the groups were compared with independent t-tests. The primary finding was that the group that experienced greater muscle damage (high CK group) generally covered significantly (p < 0.05) greater distances. This was the case for running speeds between 4 and 7 m·s -1 and, with the exception of high acceleration, all intensities of acceleration and deceleration. The high, as compared with the low, CK group also produced a significantly greater (42%) "player load." All of these significant differences were accompanied by large effect sizes. Group-specific Pearson (r) correlations between CK level and GPS variables suggest that a certain volume of movement is required before the elicitation of a positive relationship beyond trivial or small. Correlations between CK and running speeds >4 m·s -1 and moderate-high acceleration and deceleration were negative in the low CK (lesser volumes) group. With the exception of low-intensity acceleration/deceleration, the same relationships were positive and generally of a moderate-to-large magnitude in the high CK (greater volumes) group. It may be that a certain volume of movement is required for that movement to be strongly associated with CK levels. It was concluded that selected GPS variables obtained from ARF games can be used as indicators of muscle damage, and this information may be used to individualize recovery strategies after games. © 2012 National Strength and Conditioning Association.
- Authors: Young, Warren , Hepner, Jamie , Robbins, Daniel
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 26, no. 2 (2012), p. 492-496
- Full Text:
- Reviewed:
- Description: The purpose of this study was to determine if there is an association between variables that describe movements in an Australian Rules football (ARF) game with muscle damage. Fourteen elite junior ARF players were monitored with a global positioning system (GPS) during a match, and muscle damage was estimated by determining creatine kinase (CK) 24 hours postmatch. The players were median split based on CK levels, into a high and low CK group, and the groups were compared with independent t-tests. The primary finding was that the group that experienced greater muscle damage (high CK group) generally covered significantly (p < 0.05) greater distances. This was the case for running speeds between 4 and 7 m·s -1 and, with the exception of high acceleration, all intensities of acceleration and deceleration. The high, as compared with the low, CK group also produced a significantly greater (42%) "player load." All of these significant differences were accompanied by large effect sizes. Group-specific Pearson (r) correlations between CK level and GPS variables suggest that a certain volume of movement is required before the elicitation of a positive relationship beyond trivial or small. Correlations between CK and running speeds >4 m·s -1 and moderate-high acceleration and deceleration were negative in the low CK (lesser volumes) group. With the exception of low-intensity acceleration/deceleration, the same relationships were positive and generally of a moderate-to-large magnitude in the high CK (greater volumes) group. It may be that a certain volume of movement is required for that movement to be strongly associated with CK levels. It was concluded that selected GPS variables obtained from ARF games can be used as indicators of muscle damage, and this information may be used to individualize recovery strategies after games. © 2012 National Strength and Conditioning Association.
Physical qualities predict change-of-direction speed but not defensive agility in Australian rules football
- Young, Warren, Miller, Ian, Talpey, Scott
- Authors: Young, Warren , Miller, Ian , Talpey, Scott
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 29, no. 1 (2015), p. 206-212
- Full Text:
- Reviewed:
- Description:
The purpose of this study was to determine the relationships between selected physical qualities, change-ofdirection (COD) speed, and defensive agility performance in Australian Rules football players. Twenty-four male communitylevel players were assessed on sprint acceleration (10-m time), maximum strength (3 repetition-maximum half squat), leg power (countermovement jump), reactive strength (drop jump), and a single COD speed test and a defensive agility test. Change-of-direction speed was correlated with reactive strength (r = 20.645, p = 0.001) and sprint acceleration (r = 0.510, p = 0.011). Multiple regression indicated that the combined physical qualities explained 56.7% of the variance associated with COD speed (adjusted R
2 = 0.567, p ≤ 0.05). Participants were median split into faster and slower COD speed groups, and these were compared by independent t-tests. The faster group was significantly better (p ≤ 0.05) on the sprint acceleration and reactive strength tests (large effect size). The correlations between physical qualities and agility were trivial to small (r = -0.101 to 0.123, p > 0.05) and collectively explained only 14.2% of the variance associated with agility performance (adjusted R2 = -0.142, p > 0.05). When faster and slower agility groups were compared, there were trivial to moderate differences (p > 0.05) in all physical qualities. It was concluded that reactive strength and sprint acceleration are important for COD speed, but the physical qualities assessed are not associated with defensive agility performance. For agility tasks similar to those in this study, sprint and resistance training should not be emphasized, and training other factors, such as the development of sportspecific technique and cognitive skill, is recommended. © 2015 National Strength and Conditioning Association.
- Authors: Young, Warren , Miller, Ian , Talpey, Scott
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 29, no. 1 (2015), p. 206-212
- Full Text:
- Reviewed:
- Description:
The purpose of this study was to determine the relationships between selected physical qualities, change-ofdirection (COD) speed, and defensive agility performance in Australian Rules football players. Twenty-four male communitylevel players were assessed on sprint acceleration (10-m time), maximum strength (3 repetition-maximum half squat), leg power (countermovement jump), reactive strength (drop jump), and a single COD speed test and a defensive agility test. Change-of-direction speed was correlated with reactive strength (r = 20.645, p = 0.001) and sprint acceleration (r = 0.510, p = 0.011). Multiple regression indicated that the combined physical qualities explained 56.7% of the variance associated with COD speed (adjusted R
2 = 0.567, p ≤ 0.05). Participants were median split into faster and slower COD speed groups, and these were compared by independent t-tests. The faster group was significantly better (p ≤ 0.05) on the sprint acceleration and reactive strength tests (large effect size). The correlations between physical qualities and agility were trivial to small (r = -0.101 to 0.123, p > 0.05) and collectively explained only 14.2% of the variance associated with agility performance (adjusted R2 = -0.142, p > 0.05). When faster and slower agility groups were compared, there were trivial to moderate differences (p > 0.05) in all physical qualities. It was concluded that reactive strength and sprint acceleration are important for COD speed, but the physical qualities assessed are not associated with defensive agility performance. For agility tasks similar to those in this study, sprint and resistance training should not be emphasized, and training other factors, such as the development of sportspecific technique and cognitive skill, is recommended. © 2015 National Strength and Conditioning Association.