Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.
Get on all fours with your hands underneath your shoulders and your knees underneath your hips. Lift your right leg, knee bent and foot flexed, to about hip height, then extend your knee so your leg is parallel with the floor. Bend your knee back to 90 degrees, then lower your leg back underneath you without touching down. Go right into the next rep. Complete all reps on one side, then switch.