Exercise makes you more intelligent and improves your grades!

This is seriously interesting stuff. I will not promote Exercising in this article for personal, philosophical reasons or self-praise for those of you who are already regularly physically active. I will just have you have a look at some solid, recent data. Really, this is going to be a tough one for those who refuse to exercise...

Let's start of with some easy facts:

Peter S. Eriksson and Maria Åberg (2006): Effects Of Exercise On Plasticity And Cognition In The Adult Human Brain

This is really a very simple and yet powerful study: 36 000, 18yr old cohorts in Sweden between 1983 and 2004 were tested for their Cardiovascular Fitness and Intelligence and the result was a clear correlation (98%) between both abilities (similar results were observerd for Strength, by the way). Certainly you guys are rather critical and don't buy things like this too easily: "Henning, this doesn't mean that Fitness causes the higher intelligence. More intelligent people could simply be smart enough to choose to exercise more, since they are aware of the zillions of positive effects on their health." Although this already implies something cool about the relationship between one's IQ and "making the right choices" - I agree. You are completely right, this study doesn't provide any prove of exercise being the reason for altered intelligence. But you already knew that I wouldn't get excited like this, if I hadn't have some data for you which leaves almost no room for arguing... :

Henriette van Praag, Tiffany Shubert, Chunmei Zhao, and Fred H. Gage (2005): Exercise Enhances Learning and Hippocampal Neurogenesis in Aged Mice

Now this is stunning! Let me give you a brief summary: Y refers to young mice without access to exercise and YR refers to young mice with access to exercise (O and OR is the equivalent for old mice). The data above shows, that the mice with access to a wheel increased their Cell Number in the controlled area of the Hippocampus almost 4 (!) times as much as the non exercising group. The Hippocampus is the critical area in the brain for short- and long term learning as well as for spatial navigation. The truly amazing thing about it is though, that the same applies for old mice: Until now we thought that increases in brain-mass and neurogenesis in mammals is limited to the early ages of development. This still seems to be true to some degree, but only as long as this mammal doesn't exercise...

Still: "Dude, where is the prove that this applies for humans as it does for rats? Why should our brain work the same way like in rodents?" Here we go:

Chaddock, L., Erickson, K. I., Prakash, R. S., Kim, J. S., Voss, M. W., VanPatter, M., et al. (2010). A neuroimaging investigation of the association between aerobic fitness, hippocampal volume, and memory performance in preadolescent children.

This graph is showing the differences in Hippocampus-size between 10yr old kids with either lower or higher fitness. This is strong evidence for the hypothesis that exercising is eventually turning on different growth factors (BDNF), which alter the rate of existing neurons to survive (this is i.e. particularly interesting for preventing diseases like Alzheimer) and at the same time promoting the build up of new neurons and synapses in the brain. That those effects of exercise indeed directly carry-over to the increased ability to learn was already found by Woo and Sharpe (2003) (1), as well as by Rebok and Plude (2001) (2). I believe I don't have to tell anybody what a better memory means for your learning success and thus the outcome of i.e. your exams, as well as in any other situation in life.


If this stuff isn't make you want to work-out today, I can't think of anything else...



PS: When you are further interested in the mechanisms behind it, I can recommend this paper which I already mentioned earlier in the first Graph as a good start into the subject: Effects of Exercise on Plasticity and Cognition in the Adult Human Brain



References:

1. Woo, E., & Sharps, M. J. (2003). Cognitive aging and physical exercise. Educational
Gerontology, 29, 327-337.


2. Rebok, G. W., & Plude, D. G. (2001). Relation of physical activity to memory functioning in
older adults: the memory workout program. Educational Gerontology, 27, 241-260.