Literature on the topic remains inconclusive, but researchers from the University of Canberra have found positive results testing brain stimulation and how it can increase physical endurance. Assistant professor Andrew Flood and honours students Jane Hunt and Rebecca Byrne, using a form of stimulation called transcranial direct current stimulation, developed a study where participants perform a leg extension exercise and examine if the electric stimulation can extend endurance times. Ms Byrne's study targeted a reduction in pain perception to enhance endurance. Ms Hunt's research stimulated the motor cortex and evaluated a participant's mood during the test to see if it had an affect on their endurance output. Dr Andrew Flood and honours students Jane Hunt and Rebecca Byrne have been testing how electric brain stimulation can increase endurance. Credit:Elesa Kurtz "The drive to the muscles, or the message to tell the muscle to contract, is predominantly coming from the motor cortex," Dr Flood said.

“What we’re trying to do is artificially stimulate that pathway. "This is one of our explanations of why transcranial direct current stimulation might be working, but I think that’s one of the questions we’re all really interested in, is not just whether transcranial direct current stimulation works but how and why it works." The team has recorded preliminary findings where results show that stimulating the motor cortex increases endurance times for the leg extension test. Dr Flood said similar research projects globally had shown improvements in learning outcomes, particularly skill execution such as shooting basketball free throws or golf putting. While the academic world might not be ready to conclude with certainty the influence of electric brain stimulation, the sporting world has embraced it with several retailers providing systems for athletes, musicians and the everyday person marketed to improve brain function.

Notably amongst these is the Halo Sport system which looks like a set of headphones that can deliver electric current to the brain, while also delivering music. Mr Cheika has used the system personally and with players he has coached. He said he's seen benefits in performance if added to a strict training regime. The Wallabies head coach Michael Cheika. Credit:Stuart Walmsley, RUGBY.com.au “I’m not going to say the guys get them and the next day they feel unreal or anything like that, it’s not like that," Mr Cheika told Fairfax Media. "It’s about consistent work and ritual and routine, like with any type of preparation."

He said it's a "one percenter, or a two percenter", referring to his belief that the stimulation improves performance by a small amount. Mr Cheika said he had seen athletes from a variety of sports use brain stimulation in rehabilitation and preparation with positive results, but stressed it depended solely on the individual and could not replace more traditional forms of training. “It's useful in the weight room, that’s where there’s a lot of single movements, technique-oriented movements that can allow you to lift heavier weights,” he said. “In some simple warm up skills, kicking, passing, simple one-movement skills, not complex movements.” With any efforts to enhance performance in sport comes questions about legalities. A World Anti-Doping Agency spokesman said brain stimulation is not illegal.

"Up to now, we have not seen compelling evidence that this method provides a performance enhancement, a risk for health, or that it violates the spirit of sport," the spokesman said. "We will continue to monitor the situation for more solid data to become available." However Dr Flood issued a warning to anyone considering DIY electric brain stimulation, which he said had become an increasing problem, with reports of burns in the worst cases. "All of us really suggest these things need to be done in controlled, lab-based settings with people that are trained how to use transcranial direct current stimulation devices with a controlled and well-regulated current," he said. Dr Flood said there was much more research required before anyone could make definitive claims in terms of its effectiveness in professional sport.