If you're a runner, this move is a must-do: it warms up the lower-body muscles, ups the heart rate, and supports ankle stabilization. Start in a small squat. Jump sideways to the left, landing on ...

Here's how to do it: In a plank position, reach your left arm back and then circle it overhead, bringing your palm back to the floor; repeat on the other side. This counts as one rep. Complete ...