Your workout doesn't just make you feel better after a crummy day; it also protects you (specifically, your brain) against debilitating bad moods. Regular aerobic exercise boosts BDNF, a brain protein that's like a fertilizer for neurons, and appears to fortify parts of the hippocampus susceptible to depression, neuroscience has revealed. Swedish researchers recently found that exercising also keeps your brain safe from harmful substances
(one is called kynurenine) that build up during stress. It does this by producing changes in skeletal muscle that can purge the blood of kynurenine before it has a chance to cause the brain inflammation that is linked to depression
. The science behind exercise's mood-boosting benefits has become so persuasive that psychiatrists at the University of Texas Southwestern Medical Center have come up with an exercise "prescription"
that they are testing to see how much
exercise some people will need to get similar antidepressive effects as those achieved by taking medication. (In the meantime, talk to your doctor about the dose that's right for you.)