>> elizabeth gallagher. you have to have a canadian passport. >> all right there, amy. thank you. >>> but we'll switch to health news and we all know that exercise is good for you but new studies are showing not only builds muscle power but brain power and our senior medical contributor dr. jennifer ashton is here with more. what's the new revelation here. >> well, we've known for a long time that exercise is good for our entire body and our heart and our waistline but we're learning more and more about how it benefits the brain on all levels. the obvious way is that it increases blood flow. whenever you're doing exercise, your heart is working, it's getting more blood to the brain. the muscles also produce a substance that combat depression so helps your mood. it makes that signaling that goes on different parts of the brain more efficient and there are substances produced that help prevent cellular damage and delay the effects -- >> what do you have to do to get the benefits. >> you...