I think everyone is sold on the idea that exercise is good for the body, assuming no contraindications. Everyone who can, should do it – it makes you physically healthier, stronger, etc.

Fewer people are aware of it’s effect on mood though, which I have discussed before. Physical exercise makes you happier, and more likely to overcome stressful setbacks that you encounter through your life. I believe it was Tal Ben-Shahar who said “Not exercising is like taking depressants.”

Fewer people still are aware of another benefit to exercise. It’s even good for the brain. Is there nothing it can’t do?

Take dementia for instance. Laurin et al (2001) looked at a huge sample of randomly selected Canadian men and women. 6,434 of these were ‘cognitively normal’ at baseline; that is, no dementia. Five years later, 4,615 people completed a follow up test which asked them about their exercise habits, as well as other tests, such as for cognitive impairment.

High levels of activity were associated with reduced risks of cognitive impairment, dementia (of any type), and Alzheimer disease. The odds of someone having Alzheimer’s in the group who exercise were half as low as those who did no exercise at all!

So it seems that regular physical activity might be a preventative factor in age related cognitive decline and Alzheimer’s. This is pretty big.

But the benefits of exercise do not seem to stop at prevention – they may actually have an augmenting effect on cognitive function in healthy adults; and the evidence for this is getting stronger.

Take Winters et al (2007) for instance. They took a group of people, got them to run around a bit, and then tested their learning performance, both immediately afterwards and long term. They found that vocabulary learning was 20% faster after intense exercise, as well as increases in a protein called brain-derived neurotrophic factor, or BDNF, and sustained BDNF was linked to greater learning success. BDNF is sort of the holy grail of cognitive enhancement, helping to support the survival of existing neurons as well encourage the growth of new neurons and synapses. This protein may explain both the preventative and enhancement effects of exercise on cognitive function.

So when you’re wondering whether to get off your ass and get to the gym today, keep this in mind – you’re not only keeping your body healthy, you’re improving your mental function and preventing cognitive decline.

This might also play a role in the timing of your exercise sessions. Try working out immediately prior to any time you need to learn. It should improve your performance.