Workouts you can do anywhere are a game changer. A trendy, well-stocked gym is nice and all, but lifting weights isn't the only way to build strength, improve your flexibility, and master new skills.

Sometimes in life, you really can't beat the old stuff. Old friends, old tunes, old movies - we love them all. And when it comes to working out, it seems we're partial to going retro too: indoor step ...