After 45, this 5-move chair circuit tests strength, balance, and endurance—finish it nonstop to prove top-tier fitness.

"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 ...

Hamstring injuries remain one of the most challenging issues in sports medicine, frequently afflicting athletes across a broad range of activities. These injuries are complex and multifactorial, ...