Exercise and brain power: how does physical activity help us think?

We might believe that the best way to improve grades at school is to spend more time studying, even at the cost of physical activity. According to research however, we might be wrong. In fact, girls and boys with high level of cardiovascular fitness do better in subjects such as English, science and maths than those less active. A healthy set of heart and lungs appear to have more influence on grades than factors such as self-esteem, parents’ income, weight at birth, prenatal smoking and your subjective academic ability.

Exercise improves goal-directed activity. This includes selecting, planning and coordinating actions, as well as ignoring distracters and managing several pieces of information at once allowing inhibition and flexible thinking. The cognitive control involved is supported by the frontal parts of the brain, which continue to develop well into our twenties. Furthermore, compared to their sedentary peers, physically active adolescents also show better memory – a function supported by the temporal region of the brain (behind the temples).

What might be more important for those of us well past our adolescent years is that exercise helps to maintain mental abilities in old age. Physical fitness at midlife reduces the risk of dementia, and in those with dementia physical activity can attenuate its progress. This is because physically active seniors tend to have larger volumes of the brain in areas that typically shrink in dementia, such as the hippocampus.

But how exactly can sport increase our academic performance and thinking power? One way is by reducing children’s disrupting behaviour and increasing their ability to attend to the task in class. Also physical activity goes in hand with better brain structure, with a larger volume of some areas. Such beneficial effect of exercise on the brain could be related to the change in the levels of the substances that stimulate the growth of brain cells. It seems that when sedentary people undertake exercise, they produce more of these growth factors immediately following activity.

In those, however, who exercise regularly, the mechanism might be slightly different. Instead of producing more of the growth substance, the brain becomes more sensitive to it. Related to thinking prowess, exercising can also make us feel more lively and energetic, allowing us to think better. This is because physical activity enhances levels of certain chemical messengers in the brain, e.g. acetylcholine. These messengers activate areas of the brain supporting cognition, emotion and arousal. Finally, in older adults exercise seems to help to recruit compensatory brain areas, which help in completing the tasks.

How much should we exercise then and what sort of exercise would be best? Opinions are mixed, but it seems that moderate aerobic activity might be optimal, although strengthening exercise also brings cognitive benefits in seniors. Before undertaking physical activity we also need to remember that exercise carries risk and that it might be worth asking our doctor for advice. One thing is certain though, the human body is a machine designed to move!

Post by: Jadwiga Nazimek