Original ResearchTraining and game loads and injury risk in elite Australian footballers
Introduction
Playing Australian football requires repeated physical contact and movements involving endurance, speed and acceleration1 over match durations of 100+ min.2 Recently, Australian Football League (AFL) interchange rates have dramatically increased, allowing players additional breaks throughout games, possibly contributing to higher mean game speeds.3 With greater player physical demands,[1], [4] injury incidence and prevalence rates have also increased.3 During 2010, each AFL club (on average) experienced 38.6 new injuries, causing a player to miss one or more games. Overall, player injuries resulted in an average of 153.8 missed games per club.3
Understanding potential mechanisms of sporting injuries is important to AFL medical and conditioning staff, as they manage their players to be fit for matches. Training and game overload is one possible cause of injury, therefore monitoring these loads in players is important. Measuring training and game loads exerted by athletes can be done by multiplying session rating of perceived exertion5 (Borg CR10 RPE) and duration (min). Previous studies have analysed the relationship between load exerted and injury risk in team sports including sub-elite6 and professional rugby league,7 soccer,8 basketball9 and cricket.10
Gabbett and Domrow6 analysed training loads and injuries of 183 sub-elite rugby league players, finding increases in odds of injury in pre-season (OR = 2.12, p = 0.01), early competition (OR = 2.85, p = 0.01) and late competition (OR = 1.50, p = 0.04) phases, for each increase in a log (150 arbitrary units) of training load. Orchard et al.10 reported cricket bowlers completing more than 50 overs in a match had a significantly increased risk (1.77 times) of injury in the next 14–21 days compared to bowlers completing less than 50 overs. The delayed effect of the load of previous weeks is important to consider when analysing load and injury relationships.
Piggott et al.11 analysed the relationship of injury and illness with weekly training load in 16 AFL players across a 15-week pre-season training phase. No significant relationships were reported between injuries or illness and training load across this period. However, studies using a larger sample and conducted over a longer time period may provide a more comprehensive understanding of the relationship between training load and injury in AFL players.
Each year approximately 4–8 new rookie players are drafted into AFL clubs, coming primarily from junior competitions and State leagues. Senior AFL players have significantly more lean body mass and bone mineral density than State junior players,12 which is likely a result of physical maturation from previous training and game loads within the elite system. Greater movement demands in the AFL compared to State leagues13 further highlights the increased physical demands required of junior or sub-elite players in making the transition into the professional AFL game and training environment. Therefore, exploring the training and game load tolerance of players with different years of experience at an elite level is important.
To date, studies of the training load-injury relationship of AFL players are limited, with the only study performed restricted to a small sample of AFL players over a pre-season period.11 Therefore, the aim of the present study was to examine the relationship between training and game loads and injury risk in AFL players from a full club squad, across an entire season. Identifying a relationship between load and injury may allow club staff to make more objective decisions on when players are at increased risk of injury.
Section snippets
Methods
Elite (n = 46) Australian footballers were involved in this prospective study. Their mean ± SD age, stature and body mass were 22.2 ± 2.9 years, 187.7 ± 7.5 cm and 85.4 ± 8.9 kg, respectively. All were from one AFL club and competed in matches in the AFL or Western Australian Football League (WAFL) during 2010. The AFL team played 22 competition matches but did not qualify for finals. All players provided informed written consent prior to participation and all data were obtained anonymously. Ethics
Results
Additional data pertaining to classifications of pre-season and in-season injuries are provided in (online) Supplementary Table A.
Injury incidence increased (χ2 = 9.37, df = 1, p = 0.002) from pre-season (21.9 per 1000 h) to in-season (32.8 per 1000 h) (Supplementary Table B). The thigh (7.3 per 1000 h, 22.2%) and hip/groin (5.9 per 1000 h, 18.1%) were the most common sites of injuries in-season, with the most common types of injuries being muscle strains (10.7 per 1000 h, 32.6%) and haematomas/contusions
Discussion
The purpose of this study was to examine whether a relationship existed between training and game loads and injury in AFL players. These results indicate injury risk is significantly higher for players who exert larger 1 (>1750 AU) and 2 weekly loads (>4000 AU) or a large previous to current week increment (>1250 AU) in comparison to lower training and game load ranges (<1250 AU, <2000 AU, <250 AU), respectively. These findings suggest that the training and game loads of elite Australian football
Conclusion
During an elite Australian football in-season, larger 1 (>1750 AU) and 2 weekly loads (>4000 AU) and substantial previous to current week change in load (>1250 AU) were found to significantly increase injury risk when compared to lower training and game load ranges (<1250 AU, <2000 AU, <250 AU), respectively. As a method to reduce the risk of injury, derived training and game load values of weekly loads and previous week-to-week load changes should be monitored individually in elite Australian
Acknowledgement
No external financial support was received for this study.
References (24)
- et al.
Quantifying movement demands of AFL football using GPS tracking
J Sci Med Sport
(2010) - et al.
The evolution of Australian football
J Sci Med Sport
(1999) - et al.
Movement pattern comparisons in elite (AFL) and sub-elite (WAFL) Australian football games using GPS
J Sci Med Sport
(2010) - et al.
Relationship between training load and injury in professional rugby league players
J Sci Med Sport
(2011) - et al.
Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules football: a case study
J Sci Med Sport
(2005) - et al.
Match analysis and the physiological demands of Australian football
Sports Med
(2010) - et al.
Injury report 2010: Australian Football League
Sport Health
(2011) - et al.
A new approach to monitoring exercise training
J Strength Cond Res
(2001) - et al.
Relationships between training load, injury, and fitness in sub-elite collision sport athletes
J Sports Sci
(2007) The development and application of an injury prediction model for noncontact, soft-tissue injuries in elite collision sport athletes
J Strength Cond Res
(2010)
Monitoring stress and recovery: new insights for the prevention of injuries and illnesses in elite youth soccer players
Br J Sports Med
Impact of training patterns on incidence of illness and injury during a women's Collegiate basketball season
J Strength Cond Res
Cited by (217)
Relationships between internal workload and injury incidence in elite youth soccer players
2023, Journal de Traumatologie du SportEpidemiology and moderators of injury in Gaelic football: A systematic review and meta-analysis
2022, Journal of Science and Medicine in SportThe COVID-19 lockdown as a model of detraining in division 1 college softball players
2024, BMC Sports Science, Medicine and RehabilitationExercise Cardiac Load and Autonomic Nervous System Recovery during In-Season Training: The Impact on Speed Deterioration in American Football Athletes
2023, Journal of Functional Morphology and KinesiologyCurrent Technologies and Practices to Assess External Training Load in Paralympic Sport: A Systematic Review
2023, Journal of Sport Rehabilitation