Exercise improves brain performance

‘To keep our brains at peak performance, our bodies need to work hard.’ That’s the lesson Dr John J Ratey draws from his review of research findings.

Dr Ratey is an associate clinical professor of psychiatry at Harvard Medical School. He draws on recent research by neuroscientists and a range of case studies to show the positive effects of exercise on both the body and the brain.

These positive effects include enhancing learning; combating anxiety, depression and stress; helping addicts regain self control; helping women manage pregnancy, PMS and the menopause; boosting the body’s immune system; strengthening the cardiovascular system; fortifying bones; reducing the risk of cancer; and delaying cognitive decline and the onset of dementia. 

So why and how does exercise have such a big effect on our bodies and our brains?

Dr Ratey explains this at several levels:

Human evolution: over tens of thousands of years we evolved as an endurance predator - walking, jogging, running and sprinting to catch the animals whose meat we needed to survive, with our bodies and brains evolving together to achieve this. As he also explains, when it comes to delaying ageing, ‘From an evolutionary perspective, exercise tricks the brain into trying to maintain itself for survival, despite the hormonal cues that it is aging.’

Neurology: with exercise unleashing, ‘a cascade of neurochemicals and growth factors…physically bolstering the brain’s infrastructure.’ One of the strengths of ‘SPARK!’ is the way Dr Ratey explains a wide range of neurological terms and processes in language a lay reader can understand. For example he describes the prefrontal cortex as the brain’s boss or CEO; the hippocampus as its cartographer; and the protein BDNF as Miracle Gro for the brain – during his extensive explanation as to how, in practice, exercise helps the brain grow and operate more effectively.    

Case studies: starting with a school district in Illinois whose focus on the physical fitness of its students led not only to minimal levels of obesity but (against the norm in the USA) to high maths and science scores in an international students test, including the top score internationally for science. 

Dr Ratey doesn’t claim that exercise is a cure all (he explains, for instance, that the PE teacher who started the Illinois fitness programme for students went on to suffer from colon cancer). He recognizes that some of the experiments in rats and mice which he refers to may not always translate to man. And, in focusing on exercise, he may not be giving full credit to other factors (such as the impact of paying attention to individuals in the fitness programmes and giving them opportunities for immediate feedback through their own heart rate monitors, over and above the exercise itself). 

However the range of both scientific evidence and human case studies is broad enough to be persuasive. 

Dr Ratey suggests that we need not only aerobic exercise but also complex activity (like dance, tennis, gymnastic or martial arts skills) for optimum effect on the brain; that we shouldn’t be afraid of stress, at least in small doses, as it can strengthen the immune system and the brain; and that exercise is one of the few ways to counter the process of ageing. 

One encouraging footnote is that Dr Ratey sees exercise as being able, at least in part, to overcome socio economic disadvantage. As he puts it, ‘Although parents may not have any immediate control over their financial situations, they can improve their kids’ chances of performing well by encouraging them to get in shape.’ 

SPARK! How exercise will improve the performance of your brain 

Dr John J Ratey and Eric Hagerman ISBN 978 1 84724 720 9 Quercus 2009 

Published 02/01/2012.

Fitness