Movement demands in Australian Rules football as indicators of muscle damage
- 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.
Reliability and validity of a novel intermittent peak running speed test for Australian football
- Authors: Mooney, Mitchell , Hunter, Jayden , O'Brien, Brendan , Berry, Jason , Young, Warren
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 25, no. 4 (2011), p. 973-979
- Full Text: false
- Reviewed:
- Description: Mooney, MG, Hunter, JR, O'Brien, BJ, Berry, JT, and Young, WB. Reliability and validity of a novel intermittent peak running speed test for Australian football. J Strength Cond Res. 25(4): 973-979, 2011-Australian football requires frequent intermittent sprinting close to peak running speed. However, tests assessing the capability to maintain intermittent peak running speed are not reported in scientific literature. Therefore, our objective is to report the reliability and validity of a novel intermittent peak running speed test. The intermittent peak running speed test required footballers to perform 10 repetitions on 25-second intervals. Each repetition required 15-m jogging, 20-m acceleration to peak speed, 10 m to sustain peak speed, 20-m deceleration, and finally a 15-m jog. Intermittent peak running speed was determined by portable global positioning system. To assess reliability, 26 footballers performed the intermittent peak running speed test on 2 occasions 3-5 days apart. Our results revealed that average peak speed had a coefficient of variation of 2.2% and an intraclass correlation of 0.91. To assess construct validity, average peak speed was compared between elite, sub-elite, and regional footballers. The average peak speed of the elite footballers (28.6 ± 1.7 km-h-1) was higher than that of the sub-elite (27.4 6 1.7 km-h -1) and regional (27 6 1.9 km-h-1) competitors (p < 0.05). Our study revealed that the intermittent peak running speed test possesses acceptable reliability and distinguishes between elite and sub-elite footballers. © 2011 National Strength and Conditioning Association.
Repeated sprint training improves intermittent peak running speed in team-sport athletes
- Authors: Hunter, Jayden , O'Brien, Brendan , Mooney, Mitchell , Berry, Jason , Young, Warren , Down, Neville
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 25, no. 5 (2011), p. 1318-1325
- Full Text: false
- Reviewed:
- Description: Repeated sprint training improves intermittent peak running speed in team-sport athletes. J Strength Cond Res 25(5): 1318-1325, 2011-The aim of this study was to compare the effect of 2 repeated sprint training interventions on an intermittent peak running speed (IPRS) test designed for Australian Rules football. The test required participants to perform 10 3 10-m maximal efforts on an 80-m course every 25 seconds, for each of which the mean peak speed (kilometers per hour) was recorded to determine IPRS. The training interventions were performed twice weekly for 4 weeks immediately before regular football training. In the constant volume intervention (CVol), sprint repetition number remained at 10 (n = 9), and in the linear increase in volume (LIVol) intervention, repetition number increased linearly each week by 2 repetitions (n = 12). Intermittent peak running speed, 300-m shuttle test performance, and peak running speed were assessed before and upon completion of training. All measures were compared to a control group (CON; n = 8) in which players completed regular football training exclusively. Intermittent peak running speed performance in CVol and LIVol improved significantly (p < 0.01) by 5.2 and 3.8%, respectively, with no change in IPRS for CON. There were no differences in IPRS changes between CVol and LIVol. Additionally, peak running speed improved significantly (p < 0.01) by 5.1% for CVol, whereas 300-m shuttle performance improved significantly (p < 0.01) by 2.6% for LIVol only. Intermittent peak running speed, 300-m shuttle performance and peak running speed were improved after 4 weeks of training; however, progressively increasing sprint repetition number had no greater advantage on IPRS adaptation. Additionally, exclusive regular football training over a 4-week period is unlikely to improve IPRS, peak running speed, or 300-m shuttle performance.
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.