Research indicates that exercise is as good for the mind as it is for the body, enhancing the ability to concentrate and solve problems, writes Dr Elaine Mulcahy
Forget reading a book or listening to music, the best way to stimulate your brain might be a trip to the gym. Physical work-outs will not only develop your biceps and abs, but your mental muscle will begin to take shape as well.
Triathlete and martial arts expert Phillip Tomporowski is convinced physical training revitalises his mind. Having not only completed 50 triathlons, but also as an associate professor of exercise science at the University of Georgia in the United States, he knows what he's talking about. He claims that exercise facilitates clear thinking by enriching the brain's ability to concentrate and make logical decisions relating to the world around us.
In 1984, a panel of experts conducting a review of research for the National Institute of Mental Health in the US concluded that exercise is positively related to several facets of mental health, such as reduced stress, anxiety and depression. Exercise has also been found to trigger elevated mood states and an overall sense of improved well-being. However, there has been little evidence to support the notion that physical exertion can help a person to think more clearly.
Convinced there was a link, Tomporowski decided to investigate the relationship between exercise and a clear head, and recently published an extensive review of 43 papers published over the past 30 years that researched the effects of exercise on the brain and, more specifically, how a bout of exercise affects performance of various mental tasks. His findings, published in the psychological journal, Acta Psychologica, show that various forms of exercise do help us to think more clearly.
So, what sort of exercise will clear the cobwebs? In a variety of different psychological and mental tests, which examined everything from focus and concentration to speed of response and decision- making, it was found that steady-paced aerobic exercise improved the brain's ability to solve problems and make good decisions quickly. After exercise, people seemed to be able to concentrate and focus much better than before. They were able to block information that was irrelevant to the task in hand, and respond much faster to relevant information. The benefits were seen in both men and women.
In one test, male soccer players were made to run on a treadmill for two 45-minute periods, with a short break in between. On three separate occasions - before they started running, after the first 45 minutes, and after the second 45 minutes - the players were shown slides depicting real-game situations. Their task was to decide what the next step in the game should be and a panel of soccer experts then judged their decisions. The panel found that the longer the soccer players had been running, the better they were at making decisions.
In another test, addition and subtraction problems were given to female runners before and after 20-minute and 40-minute runs. Like the soccer players, the women got faster and better at solving the maths problems the longer they ran.
Researchers believe acute bouts of moderate-intensity aerobic exercise work in a manner similar to that of a psycho-stimulant drug by triggering the release of hormones and chemicals such as adrenaline and noradrenaline, thought to be involved in the brain's processing systems. Their rates of production and staying power vary according to the intensity and duration of the exercise taken, but researchers assert that, typically, the benefits in the brain remain for about an hour to an hour and a half.
The type of exercise you choose to stimulate your brain doesn't matter. Tomporowski believes any activity that stimulates the nerves and muscles of the body for about 15 to 20 minutes is enough to trigger benefits in the brain. This includes all forms of exercise, from walking to rock-climbing, yoga to marathon-running.
However, there may be an upper limit to the exercise time when the beneficial effects begin to wear off, and this largely depends on the person's fitness level.
Extremely fit people can continue to exercise and improve their mental prowess for long periods. But when people attempt to exercise beyond their fitness level, fatigue takes over and the positive effects on the brain are no longer obvious.
For example, in the soccer experiment, while both experienced and inexperienced players improved in their decision-making abilities after the first 45 minutes of running, only the highly fit, experienced players continued to improve during the second 45 minutes. Similarly, it was only highly fit women who improved at solving the maths problems after 40 minutes of running, while women of both high and low fitness had improved after 20 minutes.
The research also revealed that when people exercise beyond their aerobic threshold no enhanced brain functioning is seen. Normally, when we exercise, our heart pumps blood to the muscles involved in the activity. When we exercise very hard, for example in a 100-metre running sprint, the heart cannot pump blood to the muscles fast enough and the muscles need to create their own energy supply. It is at these levels of exercise that no improved decision-making or problem-solving abilities were seen. For example, in one study, experienced orienteerers were asked to read maps while running on a treadmill at almost maximum speed. Their ability to read the maps deteriorated during, and for a short time after, the run.
These findings show a strong link between aerobic exercise and more efficient brain function. As Tomporowski puts it: "After a bout of aerobic exercise you are more sensitive to changes in the world around you, better able to make good decisions, and when you need to act, you're quicker off the mark."
Dr Elaine Mulcahy is a brain and mind science writer based in Melbourne