Pro tennis players are amongst the top elite athletes known for their stamina and determination but many may also experience mental fatigue which has potential to slash their chance at winning matches.
Much emphasis has been placed on physical fatigue and recovery in sport, but ACU Sports Performance, Recovery, Injury and New Technologies (SPRINT) researcher Dr Suzy Russell says the focus is now also turning to the cognitive side.
Dr Russell, a sports scientist exploring mental fatigue and mental recovery in elite sport, says many athletes have spoken about the challenge of finding the right balance of training and recovery - with mind and body crucial to sporting success.
When Ash Barty announced her retirement from professional tennis at the very top of her game, she hinted that mental exhaustion was one of the reasons why she chose to end her tennis career. Other athletes have spoken of the effects that mental fatigue can have on the physical, technical, and tactical aspects of their sporting performance.
While physical fatigue is a closely monitored variable in elite sport, managed by coaches and support staff through a range of sophisticated measures, mentalfatigue appears to be much less closely managed and understood.
Athletes and coaches also now acknowledge it can have a negative impact on training and competition performance.
Dr Russell says it may not immediately be picked up when athletes are experiencing mental fatigue in training or competition.
"Sport is inherently cognitively challenging," Dr Russell says. "Media engagements, study and work commitments, repetitive tasks, over-analysis, contract negotiations, the impact of travel and unfamiliar environments have been identified as causes."
Elite athletes spend years learning how to adapt to physical tiredness, and push through when the going gets tough. When it comes to mental fatigue, however, they're less likely to be educated to understand the impact or be equipped with the strategies to manage this aspect.
This is where researchers like Dr Russell and others are heading with their work: with a desire to better understand how to identify elevations in mental fatigue and apply interventions to minimise its potentially detrimental effects.
"We're starting to look at the effectiveness of various methods of training to potentially develop a tolerance to mental fatigue in a sport-specific way," she says.
"So, it's not just about avoiding mental fatigue, it's actually trying to induce it in training and get athletes used to the feeling of performing through mental fatigue, so they can adapt and perform."
"The good news is there is an interest in building an evidence base on ways to mitigate mental fatigue, and researchers have found benefit of methods such as nutritional interventions and using visual performance feedback."
Research has highlighted the detrimental impact of mental fatigue. This includes an impact on other racquet sports, such as padel and table tennis, with findings including decreases in ball speed, increases in reaction time, and changes in brain activity.
"We've definitely gained a much clearer understanding of the signs and symptoms of mental fatigue for athletes, and practitioners and athletes are engaged with learning more about it," Dr Russell says.
"Emerging technologies and techniques are helping us to understand practical ways to monitor cognitive activity and provide individual training and recovery techniques to our athletes, which may help them gain those small margins that determine success."
These include proven impacts that cognitive fatigue can have not only on physical performance, but also on the lifestyle choices of athletes, potentially affecting things like diet, exercise, emotional regulation, and overall motivation.
