Experts weigh in on whether cardio kills your gains, how much protein you need, and the right mix of sweating and lifting to meet your goals.

Pick up a pair of heavy dumbbells or kettlebells. Stand tall with your shoulders back and core engaged. Walk forward with ...

Ginny MacColl, 73, got fit in her 60s and now competes in American Ninja Warrior. She started by aiming to do one pull-up.