"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Nordic curls are a bit of a gymgoer’s party trick. As you lower the backside of your body backwards ...

When you picture different athletes—marathon runners, gymnasts, and Olympic weightlifters, for example—you likely categorize them instinctively by their height, size, and build. But the differences in ...

What's the first thing that comes to mind when you think about the words twitch and muscle? Spasms, perhaps. You'd hardly be alone in thinking that. But when it comes to fitness, it's most commonly ...

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. For strong, powerful ...