Protecting the stars of tomorrow

With AFL training regimes reaching ever-more sophisticated heights, an increased risk of muscle damage and impaired game performance for younger AFL players has been identified by Deakin sports scientist Shannon Hunkin.

Ms Hunkin identified this issue during her recent honours project, which showed that younger AFL players are more vulnerable to muscle damage, resulting from inadequate recovery time after intense training and their weekly game.

She urges coaches to carefully monitor the training regimes of younger AFL players, to avoid these negative consequences and help the players achieve a full elite career.

For the project, Ms Hunkin monitored 29 AFL players, aged between 18 and 30, during the 2012 season. She measured levels of the protein creatine kinase to identify muscle damage and used coach reports and performance ranking scores to determine the effect of this damage on match performance.

Ms Hunkin undertook her research within Deakin’s Centre for Exercise and Sport Science, under the supervision of Associate Prof Paul Gastin. The centre focusses on research in areas such as coach effectiveness; measurement, analysis and prediction in sport; and sport technology.

Her research found that average levels of the protein during the football season were nearly five times higher than before pre-season training began. The footballers with higher levels of the protein, in any given week, demonstrated reduced match performance.

“During the season, players undertake a number of training sessions each week, but we have found that - for the best performance in competition - they need to be allowed to fully recover from these training sessions,” Ms Hunkin said.

She added that if levels remain high for several weeks, players are at greater risk of residual muscle damage.

Her research showed that older, more experienced footballers are less vulnerable when exhibiting muscle damage, perhaps due to “better tactical knowledge and an enhanced ability to position themselves on the field, or because their bodies have adapted to the training regime.”

Junior players - in the first two to three seasons at elite level - appear to be most at risk.

Ms Hunkin hopes that clubs will use her research to improve individual monitoring of younger players “to make sure they are developing properly and reduce the chances of injury or under-performance.”

“Improved individual monitoring would help to maximise each younger player’s game performance and, hopefully, contribute to a full-term career at elite level,” she said. “Most players only stay at the elite level for three to six years.”

Ms Hunkin said that while creatine kinase is one marker, coaches could use other indicators, such as inhibited flexibility or soreness, to identify muscle damage.

“AFL training is now more intense than it was even five to ten years ago,” she said. “In the past, there was a focus on long distance running, for instance. Now there is more emphasis on intense sprinting, altitude and heat training. During pre-season, players may go to Cairns for heat training, or Colorado for altitude training, and all of this puts strain on the athlete’s body.”

“It is a matter of finding the right balance. If less experienced players are monitored more carefully, trainers may see early warning signs and then they can ease back a bit.”