Allow a laboratory mouse to run as much as it likes, and its brainpower improves. Force it to run harder than it otherwise might, and its thinking improves even more. This is the finding of an experiment led by researchers at National Cheng Kung University in Taiwan and placed online in May.
(...) For some time, researchers have known that exercise changes the structure of the brain and affects thinking. Ten years ago scientists at the Salk Institute in California published the groundbreaking finding that exercise stimulates the creation of new brain cells. But fundamental questions remain, like whether exercise must be strenuous to be beneficial. Should it be aerobic? What about weight lifting? And are the cognitive improvements permanent or fleeting?
(...) Why should exercise need to be aerobic to affect the brain? “It appears that various growth factors must be carried from the periphery of the body into the brain to start a molecular cascade there,” creating new neurons and brain connections, says Henriette van Praag, an investigator in the Laboratory of Neurosciences at the National Institute on Aging. For that to happen, “you need a fairly dramatic change in blood flow,” like the one that occurs when you run or cycle or swim. Weight lifting, on the other hand, stimulates the production of “growth factors in the muscles that stay in the muscles and aren’t transported to the brain,” van Praag says.
(...) “It would be fair to say that any form of regular exercise,” Chauying J. Jen says, if it is aerobic, “should be able to maintain or even increase our brain functions.”
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