"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Achieving strong, defined arms or legs is about more than just lifting weights. A ton goes into growing ...

Everyone is familiar, at least hand-wavingly, with the distinction between slow-twitch and fast-twitch muscle-fiber types. The former are great for running marathons; the latter are ideal for ...

Plus, how to get the most of your walking workout.

WASHINGTON - Most people who work out have a pulling exercise somewhere in their routine - a row, a pulldown, maybe a pull-up. But far fewer could tell you which muscles they’re actually training, or ...