Do It: Stand on a six-inch step or box, hands on your hips. Squeeze your right glute, step back with your right leg, and lower until your left knee is bent at least 90 degrees. Pause, then push through the left leg to return to start. That’s one rep. Alternate sides until you’ve done all the reps for each leg.
This is the ultimate butt multitasker, providing an active hip-flexor stretch along with a calorie-blasting lunge/step-up combo. Whew!