Illustration: Joel Holland
Do the following exercises for 30 seconds each, shifting to the next one in the sequence without resting. Repeat the circuit two to six times (pause for 90 seconds between each), depending on your fitness level.
1. Squat Jacks
Perform jumping jacks in a squat position.
2. Knee Tucks with Push-Ups
Position yourself in the "up" phase of a push-up, then hop both knees forward toward your chest. Jump your legs back to your original stance and do a push-up. Repeat.
3. Jump Squats
Return to a squat pose and leap as high as you can, landing with your knees bent. Repeat.