You need: a towel, your floor
Moves: Do each move for 30 seconds; then rest for 15 seconds. Do 4 rounds.
Assume a plank position, your toes on the towel. Using your forearms, push your body back as far as you can, sliding the towel along. Return to the starting position. Maintain a tight core and squeeze your glutes throughout the move.
Lie on your back with legs straight, knees together, and arms extended over your head. Press your lower back into the floor and contract your abs to lift your shoulders just off the floor. Then lift your legs off the floor and hold.
Plank Rear Delt Raise
Assume a pushup position. Extend your right arm out to the side, squeezing your shoulder blades together. Return to the pushup position and repeat. Continue for 30 seconds and then repeat with your left arm.
Towel Reverse Lunge
Stand with your right foot on a towel. Slide your right foot backward on the towel, bending your left knee. Stand up by driving through your left foot and sliding your right foot forward. Do reps for 30 seconds. Switch sides and repeat.
Towel Leg Curl
Lie on your back with your legs straight out and both heels on a towel. Slide your feet back toward your hips as you lift your lower back off the floor, squeezing your glutes and hamstrings. Return to the starting position and repeat.
Stand with your feet hip-width apart. Push your hips back and lower your body until your thighs are nearly parallel to the floor. Explosively stand up and jump. Let your knees bend as you land; then drop into another squat and jump again.