Aging shrinks your brains; cardio makes them grow
After the age of thirty your brain starts to shrink. The process starts very, very slowly, but as you get older the rate at which this happens starts to rise. If you live long enough dementia is inevitable, you might think. Psychologists at the University of Pittsburgh discovered that you can reverse the brain's decline by running three times a week for 40 minutes.
Aging & hippocampus
One of the crucial organs in the brain is the hippocampus. The better this organ functions, the better your memory. In a 60 year old the hippocampus shrinks by 1-2 percent a year. Sounds alarming – and it is – but neurologists regard this an inevitable consequence of aging.
Nevertheless, there are indications that physical exercise can delay, stop and maybe even reverse this process. If you get elderly people to run for an hour at 70 percent of their maximal heart rate three times a week, their brain volume will have increased after six months. [J Gerontol A Biol Sci Med Sci. 2006 Nov; 61(11): 1166-70.] Reviews suggest that cardio training helps the brains of healthy old people to function better. [Cochrane Database Syst Rev. 2008 Jul 16;(3): CD005381.]
The researchers did an experiment with 120 healthy men and women with an average age of 66. Half of the test subjects did stretch exercises three times a week for a year; the other half ran for 40 minutes three times a week at 60-75 percent of the VO2max. That's at a pace at which it starts to get impossible to hold a conversation.
The volume of the hippocampus of the subjects that did stretch exercises decreased during the course of the experiment. The opposite happened in the subjects that ran: the volume of the hippocampus increased by two percent in these subjects.
The researchers measured the subjects' maximal oxygen uptake to assess their fitness and discovered that the fitter the subjects became, the more their hippocampus grew.
The researchers also figured out how training caused the hippocampus to grow. Running boosted the production of brain-derived neurotrophic factor [BDNF]. BDNF has approximately the same effect on the brain as anabolic steroids have on muscle tissue.
Lastly, the researchers got their subjects to do memory tests. The more the hippocampus had grown, the better the memory scores.
Oh yes. If BDNF is indeed a key factor in the positive effect of exercise on the brains, taking beta-alanine as a supplement might enhance this effect. There you go: a free tip from the Ergo-Log editors.
Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):3017-22.
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