Push-up into unstable plank
Come into push-up position with feet hip-width apart, hands directly under shoulders, and body in straight line from head to heels. Inhale and bend elbows to lower body toward the floor. Exhale and explode back up, raising left arm and right leg at top of push-up so they’re parallel to floor. Repeat on opposite side; that’s 1 rep. Do 10-20 reps.