Accelerometer load as a measure of activity profile in different standards of netball match play
- Authors: Cormack, Stuart , Smith, Renee , Mooney, Mitchell , Young, Warren , O'Brien, Brendan
- Date: 2014
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 9, no. 2 (2014), p. 283-291
- Full Text: false
- Reviewed:
- Description: To determine differences in load/min (AU) between standards of netball match play., Methods: Load/ min (AU) representing accumulated accelerations measured by triaxial accelerometers was recorded during matches of 2 higher- and 2 lower-standard teams (N = 32 players). Differences in load/min (AU) were compared within and between standards for playing position and periods of play. Differences were considered meaningful if there was >75% likelihood of exceeding a small (0.2) effect size., Results: Mean (± SD) full-match load/min (AU) for the higher and lower standards were 9.96 ± 2.50 and 6.88 ± 1.88, respectively (100% likely lower). The higher standard had greater (mean 97% likely) load/min (AU) values in each position. The difference between 1st and 2nd halves' load/min (AU) was unclear at the higher standard, while lower-grade centers had a lower (-7.7% ± 10.8%, 81% likely) load/min (AU) in the 2nd half and in all quarters compared with the 1st. There was little intrastandard variation in individual vector contributions to load/min (AU); however, higher-standard players accumulated a greater proportion of the total in the vertical plane (mean 93% likely)., Conclusions: Higher-standard players produced greater load/min (AU) than their lower-standard counterparts in all positions. Playing standard influenced the pattern of load/min (AU) accumulation across a match, and individual vector analysis suggests that different-standard players have dissimilar movement characteristics. Load/min (AU) appears to be a useful method for assessing activity profile in netball. © 2014 Human Kinetics, Inc.
The relationship between physical capacity and match performance in elite Australian football : A mediation approach
- Authors: Mooney, Mitchell , O'Brien, Brendan , Cormack, Stuart , Coutts, Aaron , Berry, Jason , Young, Warren
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 14, no. 5 (2011), p. 447-452
- Full Text:
- Reviewed:
- Description: The aim of this study was to verify if yo-yo intermittent recovery test (level 2) (yo-yo IR2) score is linked to Australian football (AF) performance through match exercise intensity. Six week prospective study design. Twenty-one data sets were recorded from nine individual players that completed the yo-yo IR2, and played an Australian Football League match in the first five rounds of the 2010 season wearing a global positioning system (GPS) unit. Simple mediation modelling was used to analyse the inter-relationship between yo-yo IR2 score, match exercise intensity and AF performance. Playing position and experience were also incorporated into the model to identify conditional affects. A significant direct relationship was observed between yo-yo IR2 and number of ball disposals (p<0.1) and a significant indirect relationship was observed between yo-yo IR2 and number of ball disposals through distance travelled at high intensity (HIR mmin-1) (p<0.1). Moderation analysis showed that playing position affected the relationship between of yo-yo IR2 and HIR mmin-1 (p<0.1) and HIR mmin-1 and total ball disposals (p<0.1). Playing experience also significantly affected the relationship between HIR mmin-1 and total ball disposals. This study is the first to identify the effects of yo-yo IR2 on total ball disposals through HIR mmin-1 performed during AF matches, and that playing position and playing experience affect these interactions. © 2011 Sports Medicine Australia.
Which jump variables should be used to assess explosive leg muscle function?
- Authors: Young, Warren , Cormack, Stuart , Crichton, Michael
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 6, no. 1 (2011), p. 51-57
- Full Text:
- Reviewed:
- Description: Purpose: The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance. Methods: Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (flying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated. Results: Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001). Conclusions: The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.
The use of sprint tests for assessment of speed qualities of elite Australian rules footballers
- Authors: Young, Warren , Russell, Andrew , Burge, Peter , Clarke, Alex , Cormack, Stuart , Stewart, Glenn
- Date: 2008
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 3, no. 2 (2008), p. 199-206
- Full Text:
- Reviewed:
- Description: Purpose: The purpose of this study was to determine the relationships between split times within sprint tests over 30 m and 40 m in elite Australian Rules footballers. Methods: Data were analyzed from two Australian Football League (AFL) clubs. The first club (n = 35) conducted a 40-m sprint test and recorded split times at 10 m and 20 m. The second club (n = 30) conducted a 30-m sprint test and recorded splits at 10 m and 20 m. Analyses included calculation of Pearson correlations and common variances between all the split times as well as "flying" times (20-40 m for the first club and 20 to 30 m for the second club). Results: There was a high correlation (r = 0.94) between 10-m time and 20-m time within each club, indicating these measures assessed very similar speed qualities. The correlations between 10-m time and times to 30 m and 40 m decreased, but still produced common variances of 79% and 66% respectively. However when the "flying" times (20-40 m and 20-30 m) were correlated to 10-m time, the common variances decreased substantially to 25% and 42% respectively, indicating uniqueness. Conclusions: It was concluded that 10-m time is a good reflection, of acceleration, capabilities and either 20 to 40 m in a 40-m sprint test or 20 to 30 m in a 30-m sprint test can be used to estimate maximum speed capabilities. It was suggested that sprint tests over 30 m or 40 m can be conducted indoors to provide useful information about independent speed qualities in athletes. © 2008 Human Kinetics, Inc.
- Description: C1
Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules football : A case study
- Authors: Young, Warren , Newton, Robert , Doyle, Tim , Chapman, Dale , Cormack, Stuart , Stewart, Glenn , Dawson, Brian
- Date: 2005
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 8, no. 3 (Sep 2005), p. 333-345
- Full Text:
- Reviewed:
- Description: A purpose of this study was to determine if pre-season anthropometric and physiological measures were significantly different for the players from one Australian Football League (AFL) club selected to play in the first game of the season compared to the players not selected. Another purpose was to compare fitness test results for defenders, forwards and mid-fielders in the same AFL club. Thirty-four players were tested for isolated quadriceps and hamstrings strength, leg extensor muscle strength and power, upper body strength, sprinting speed, vertical jump (VJ), endurance, skinfolds and hamstring flexibility. The starters who were selected to play the first game were a significantly older and more experienced playing group, and were significantly better (p < 0.05) in measures of leg power, sprinting speed and the distance covered in the Yo Yo intermittent recovery test compared to the non-starters. Although there were trends for the superiority of the starters, the differences in lower and upper body strength, VJ and predicted VO(2)max were nonsignificant. The forwards generally produced the worst fitness scores of the playing positions with the midfielders having significantly lower skinfolds and the defenders possessing better hamstring strength and VJ compared to the forwards. It was concluded that some fitness qualities can differentiate between starters and non-starters, at least in one AFL club. Comparisons of playing positions and the development of fitness norms for AFL players require further research.
- Description: C1
- Description: 2003001187