There certainly is some scientific evidence to support the claim that exercise can improve a person’s ability to think more clearly. But, there is also evidence to show that fatigue and over-training will not help the brain. In fact, exercising to exhaustion really has little benefit in any sense and is more likely to take you one step forward but two steps back.

Exercise has been found to trigger elevated mood states and an overall improved sense of well-being and helps to keep stress, anxiety and depression to a minimum. Now a new study has shown that exercise can also have some short-term benefits on mental fitness. Phillip Tomporowski, an exercise scientist at the University of Georgia in the USA, has competed in about 50 triathlons and recently reviewed 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 our performance on various mental tasks. His findings, published in the psychological journal Acta Psychologica, show that various forms of exercise actually can help us to think more clearly. (1)

So, what sort of exercise will clear the mind? In a variety of different psychological and mental tests that examined everything from focus and concentration to speed of responding and decision-making, it was found that steady-paced aerobic exercise improved the brain’s ability to solve problems and make decisions fast and effectively. After exercise, people seemed to be able to concentrate and focus much better than before. They were better able to block information that was irrelevant to the task at hand, and responded much faster to information relevant to the task. The benefits were seen in both men and women.

One test the scientists used to measure improved focus and concentration was the Stroop test. The Stroop test was invented by J Ridley Stroop back in the 1930’s and is still widely used by psychologists today. The faster a person is at completing the Stroop test, the more focused they are. Try it yourself before and after a run or a bike-ride and see if you improve. (Coming Soon)

Decision-making and problem solving ability were also found to improve after exercise. 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 job 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. (2)

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 rate of production and staying power are largely dependent on the intensity and duration of the exercise, but researchers predict that typically the benefits in the brain remain for about an hour to an hour and a half.

However, there may be an upper-limit to the duration of the exercise session, 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 for long periods and continue to improve their mental prowess. But, when people attempt to exercise outside the boundaries of 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 both women of high and low fitness had improved after 20 minutes.

Many unfit people set out to begin an exercise routine with great ambition and force and then find that they cannot stick to the routine and their motivation quickly disappears. These people end up on a never-ending cycle of great ambition, loss of motivation, and a steady slump back to where they started – on the sofa watching Big Brother. If this is you, you need to re-think your strategy. The reason you are not sticking to the routine is probably because you are not enjoying it. Exercise is meant to be fun and if you don’t come home feeling good, chances are you have gone too far. Coming home feeling bad means you will be less motivated to go out and do it again tomorrow and so the negative emotions begin to take control.

There is no need to go out hard or expect too much when you first start to exercise. Physical fitness is something that gradually builds up over time; it does not appear over-night. And, it requires consistency in order to appear at all. Start with short walks and gradually increase the distance and speed one day at a time. Phillip Tomporowski believes that any activity that stimulates the nerves and muscles of the body for about 15 to 20 minutes is enough to trigger the benefits in the brain. This includes all forms of exercise from walking to rock-climbing and yoga to marathon running.

The research also found that when people exercise at very high intensities no enhanced brain functioning is seen. Normally when we exercise our heart pumps blood to the muscles involved in the activity. When we exercise really hard, for example in a 100m 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 orienteers were asked to read maps while running on a treadmill at almost maximum speed. Their ability to read the maps actually deteriorated during and for a short time after the run. Unless you are an athlete in training for a race most exercise can be done aerobically. Stick to steady-paced exercise and use the talk-test; you should be able to hold a conversation with your running or riding partner without feeling out of breath.

In short, regular aerobic exercise will clear the cobwebs and help your brain to function more efficiently. 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.”

On the other hand, exercising too hard and exercising beyond your fitness level will not help you to think more clearly. The fitter a person is, the more they will reap the rewards from aerobic exercise. Physical fitness does not come easy. The best strategy is to gradually increase the duration of your exercise sessions and, along with enhancing your physical fitness, your mental muscle will also begin to take shape.

Train Smart!
Elaine Mulcahy, PhD

References:

1) Tomporowski PD, Effects of acute bouts of exercise on cognition.
Acta Psychologica (Amst). 2003 Mar;112(3):297-324

2) Marriott T., Reilly T., Miles (1993). The effect of physiological stress on cognitive performance in a simulation of soccer. In T. Reilly, J. Clarys, A. Stibbe (Eds.), Science and Football II (p 261-264). London: E and FN Spon.