While it's not "all in your head", physical fitness and athletic performance are widely dependent on mental endurance. Feeling stressed and mentally drained can have a huge effect on how you perform physically, with mental fatigue likely to decrease your motivation, increase the time you take to recover, and impact your lifestyle choices. According to a new University of Queensland study, the brain may play a more important role in physical fitness than first thought.

While emphasis is usually placed on physical fatigue and recovery in the context of sport, according to University of Queensland researcher Suzy Russell, much more needs to be done on the cognitive side. "We need to think more about the brain in athletes and how it's influencing their sporting performance," she said, adding "[This research] gives us a bit more of an idea that it's something we need to be looking at in terms of our application to sport."

The study involved months of work with the Queensland Firebirds netball squad. Before each training sessions, 10 contracted Firebirds players were asked questions, with their saliva also tested for the stress markers cortisol and alpha-amylase. This gave the scientists a chance to evaluate the players based on both subjective performance measures and internal stress markers. According to Ms. Russell, "They basically are hormonal or stress responses to your external environment and how you're reacting internally."

Over the 16-week test period, the players who felt physically tired saw little effect on their training, while those who felt mentally drained thought their performance on the court suffered. Managing mental fatigue may be even more important than managing physical fatigue, with the link between the brain and body responsible for how we function both on and off the court. This goes both ways, with any kind of fatigue likely to influence cognitive performance and degrade performance outcomes.

From limiting your attention span and compromising your decision making through to degrading reaction times and quality of skill execution, paying attention to your brain is critical for anyone who works their body. As it turns out, cognitive factors can affect physical performance in multiple ways, from decreased motivation levels and resilience during training through to longer recovery times. Mental and emotional exhaustion are also known to have a negative impact on lifestyle choices, with excessive food consumption and alcohol use linked to stress and exhaustion.

Brain endurance training may be the answer, with this computer-based training protocol developed by Samuele Marcora with the aim to reduce mental fatigue and perception of effort. Part of this training involves working out in front of a computer as your brain responds to on-screen stimuli while your legs work hard on a stationary bike. While the research is in its early stages at this point, there is evidence to suggest that brain endurance training can increase resilience to mental fatigue. With the right combination of work for body and mind, it may be possible to change your perception of effort and improve your physical performance.