Reduce your waistline, expand your mind


Regular exercise has far more benefits than just a lean body and sense of achievement, writes Barry Singleton

Exercise is good for you, and not just good for your health. By exercising regularly we ‘will be leaner, smell nicer, be more attractive to the opposite sex’, as the Vice-President for Students Martin Butler reminded us in a recent email.

Many may share Dr Butler’s apparent concern that UCD students aren’t as attractive as they could be. Or perhaps he is really concerned with our health, but realises that we’re more likely to be motivated by rewards we can cash-in on while young.

Idle speculation aside, for a message from a man whose primary interest is in education, there was one benefit of exercise that was conspicuous by its absence: it makes you smarter.

This may seem surprising; we’re inclined to think of the mental and physical, mind and body, as fundamentally different. Nor does it fit with the ‘jock’ and ‘nerd’ stereotypes.

Our minds, however, are limited by our physical brains, as anyone who has encountered a concussion or cognac will attest to. We can change our minds by changing our brains. But how does exercise do that?

Take a broader perspective from the viewpoint of evolution, and you see just how closely related movement and cognition are. After all, only organisms that move have brains. The brain evolved from and controls the nervous system in animals, which itself came about because of the need to predict and respond to stimuli encountered in physical space. As neuroscientist Rodolfo Llinás puts it: “That which we call thinking is the evolutionary

internalization of movement.”

Given that active movement was the original evolutionary imperative for brain growth, it makes sense that exercise and brain function are closely related. But how does exercise make you smarter?

Acquiring knowledge involves the creation and maintenance of connections between brain cells, or neurons. In order to do this, cells are dependent on what are called factors, the main one being brain-derived neurotrophic factor, or BDNF. This factor is present in a part of the brain called the hippocampus, which is related to memory and learning.

Learning itself increases BDNF levels in the brain. But so does exercise. The lesson is simple: if you want to prime your brain, move. In one study, people learned vocabulary twenty per cent faster after exercise than before, and this correlated with BDNF levels.

Moreover, exercise not only helps create and maintain connections between existing neurons, but spurs the development of new cells in the hippocampus as well.

The other important way in which exercise makes you smarter is that it improves your willingness to learn. Exercise means increased attention and motivation – ‘self-discipline’, a trait that has a strong positive correlation with scholastic achievement.

Exercise boosts dopamine, which is one of the main brain chemicals or neurotransmitters.

This neurotransmitter is all about motivation and attention; it calms the brain down and enables one to focus. In fact it is this neurotransmitter that is the target of attention deficit medications such as methylphenidate. But we don’t need a full-blown attention deficit disorder in order to benefit from more dopamine.

Regular exercise increases dopamine storage in the brain and also initiates a process which ultimately creates dopamine receptors in the reward centre of the brain, making us more sensitive to the neurotransmitter. Serotonin is another neurotransmitter equally affected by exercise and is important for mood and impulse-control.

As well as improving our mood and making it easier to learn, exercise also offers protection against those things which can set us off in the opposite direction, namely; stress, anxiety and depression.

So you may be asking: what exercise do I need to do in I order to boost my brain? There are three crucial factors. First, it must be aerobic, that is it involves elevating your heart rate and breathing for a sustained period of time. Second, it must be combined with some sort of learning; use those new connections and nerve cells or lose them! And finally, it must be continuous. You could go for morning runs before the start of lectures, or learn martial arts and so on – just pick something you enjoy and stick to it.

What about strength training? Little is known about the effects of strength training on the brain, yet some gym-goers and bodybuilders might unwittingly be doing something to boost their cognition. Creatine, a popular supplement and substance found naturally in low quantities in meat, is stored in muscle tissue. But creatine is also stored in the brain, where it increases the availability of energy to neurons. It has been demonstrated that supplementation of five grams a day over a six-week period significantly increases scores on fluid intelligence (at least in vegetarians).

So move. Get smarter. And you’ll be more attractive too.