Perform this 5-minute series of exercises 2 to 4 times, avoiding rest between rounds if you can. 1. 40 seconds of cross jacks / 20 seconds rest 2. 40 seconds of frogger / 20 seconds rest 3. 40 seconds of high-knee skips / 20 seconds rest 4. 40 seconds of plank jacks / 20 seconds rest 5. 40 seconds of air squats / 20 seconds rest Cross Jacks Stand with your feet shoulder-width apart and extend your arms fully to the sides at shoulder height, palms facing down. Jump and cross your right arm over your left arm, right foot over left foot. Jump your feet slightly wider than hip-distance and uncross your arms. Then, jump again, this time crossing your left arm over your right arm, left foot over your right foot. Frogger Begin in a high plank position, with your legs fully extended behind you, arms fully extended under your shoulders. Jump your feet outside of your hands, landing in a deep squat. Then, jump your feet back to starting position. High Knee Skips From a standing position, tighten your abs and hop on your right leg, while bringing your left knee up to your chest. At the same time pump your right arm up towards your face. Switch legs and continue alternating. Plank Jacks Begin in a high plank position, with your legs fully extended behind your, arms fully extended under your shoulders, core tight. Point your face at the floor or mat. Keeping your pelvis steady, jump your feet wide, then back together. Air Squats Stand with your feet slightly wider than hip-distance apart, toes pointed outward slightly. Keeping your chest lifted, sit back into a squat until your thighs are parallel to the floor and raise your arms towards the ceiling. Push through your heels to return to starting position and repeat.