Squat Thrust Runs
Credit: Justin Lambert / Getty Images

As you drop into the squat, kick both legs behind you and catch yourself with your arms. These aren't pushups, though, so keep your arms straight. Pop back into an upright position and run in place before your next squat.

Advanced version: Do a sprawl run. Instead of supporting yourself with outstretched arms, allow your chest and hips to touch the floor before you get back on your feet.

Brett's Tip: Exhale and raise your abs as you kick your legs back. This helps prevent lower back injuries.