News

Breakthrough on the Horizon

Published 26 October 2011

The BBC's Horizon science programme has been filming at the University of Brighton where research is unravelling the mystery of how the brain determines how much exercise we are capable of.

They filmed science journalist Dr Michael Mosley at the university's Sport and Exercise Science department at Chelsea School of Sport in Eastbourne for a programme called "The Truth about Exercise", scheduled for broadcast in January.

Although the limits to human performance have been explored for decades, only within the last 15 years has the study of the brain's involvement in exercise tolerance become debated by sport and exercise scientists. Scientists hope the research could lead to new methods of improving performance.

PhD student Rosie Twomey (back left), carrying out brain stimulation on Dr Michael Mosley, assisted by MSc student Jo Sansom and supervised by Dr Emma Ross (right), photo courtesy of the BBC

Originally, researchers assumed that fatigue was caused because muscles couldn't operate effectively as a consequence of prolonged or intense physical exertion. However, the introduction of techniques such as "transcranial magnetic stimulation", a non-invasive method used to assess the brains control of muscles, has allowed researchers to explore just how influential the brain is in muscle fatigue.

Dr Mosley, fronting the Horizon programme, spent time in the school's hypoxic chamber, where results showed that as his blood oxygen levels became low, his brain signaled to his muscles that he was incapable of continuing to exercise.

Dr Emma Ross, senior lecturer at Chelsea School of Sport, said: "We have been investigating how the brain is involved in exercise performance, and how the nervous system – not just our muscles – dictates how much physical activity we are capable of doing."

Dr Ross' research team previously has shown that in conditions of low oxygen, known as hypoxia, the brain regulates our ability to exercise more so than in normal conditions. In a paper published in The Journal of Applied Physiology the team demonstrated that during exercise, the brain contributes to around 18 per cent of fatigue at sea level but 54 per cent in conditions of low oxygen.

She said: "Interestingly, in the low oxygen trial the participants muscles still had significant function even though the individuals could not carry on exercising – the brain was regulating their ability to perform physical activity very tightly because of the threat to physiological balance (known as homeostasis) imposed by the low oxygen."