Exercise and the brain: latest findings from mice to men

I previously discussed how exercise is becoming increasingly recognized as a treatment for psychiatric disorders, thanks to recent research reporting beneficial effects of exercise on mental health and cognition. Most studies have examined effects of aerobic/cardiovascular exercise, but an interest in resistance training is growing. Let’s take a look at three of the latest studies on different types of exercise and the brain. I’ll summarize one study of mice, one of monkeys, and one of humans.

1. Mice

David Creer and colleagues reported in PNAS that mice who exercised on a running wheel were better able to discriminate between visual patterns than mice who didn’t exercise. This enhanced “spatial pattern separation” was linked to increased neurogenesis in the hippocampus of exercising rats. Neurogenesis, the birth of new neurons, has repeatedly been demonstrated in exercising mice, but the precise function of neurogenesis is unknown. So Creer’s study not only shows that exercise improves a cognitive ability that hadn’t previously been found, but the study also provides insight into a possible function of neurogenesis.

2. Monkeys

The effects of exercise on the brain of monkeys is a relatively untapped area, but such study of our primate relatives could provide better insight into what exercise does for humans. In a paper currently in press, researchers report that monkeys who ran on treadmills for 1 hour a day, 5 days a week (comparable to recommended exercise regimens for humans) for a period of 5 months had greater cortical vasculature (i.e., more blood supply) in their brains than monkeys who didn’t exercise. The exercising monkeys also learned to participate in cognitive tasks faster than their sedentary counterparts, but their actual performance on the cognitive tasks wasn’t enhanced.

3. Humans

To build on the study I mentioned in my previous post on the beneficial effect of resistance training on cognitive function in elderly woman, researchers in Brazil have reported that resistance training is also good for elderly men. A group of 65-75 year olds were put on a 24 week weightlifting exercise program, and the exercisers subsequently reported improvements in mood and anxiety relative to a control group. The improvements were linked to an increased blood level of IGF-1, a hormone that also acts on the brain and may underlie cognitive and mental health benefits of exercise.

So there you have it. Exercise demonstrates time and again that it exerts positive effects on the brain. Different exercise types seem to have different effects, but all types are beneficial in some way. More investigations on this topic are sure to come, giving insight to the treatment and prevention of neurological and psychiatric disorders.