Got a minute to spare? Then we've got an exercise for you! This is a quick-and-easy move that can be done virtually anywhere at any time, whether you're waiting for water to boil in your kitchen or sitting through commercials in your living room.

The Standing Knee Tuck works your entire core, helping to flatten your belly and strengthen your hamstrings and butt.

In this video, health expert Cynthia Sass, RD, demonstrates the move: Start by standing and lift your left leg straight back, hinging forward at the hips, and reaching your hands straight ahead. Keep your hips level and body straight from hands to heel. In one move, bring your knee up and elbows back, creating a powerful standing crunch.  Do 25 on each side.

Add these leg and butt moves and these ab moves for a well-rounded workout.