Perform 50 reps of each exercise in any order as quickly as you can without rest. You don’t have to do all 50 reps in a row—you might do 20 pushups, move on to jumping jacks, do another 15 pushups, and so on. Once you complete the circuit, rest 1 to 2 minutes and repeat. Do up to 3 circuits total, starting with a different move each time.
Drop down on all fours and place your hands on the floor so they’re straight and slightly beyond shoulder width. Lower your body until your chest nearly touches the floor, and then push yourself back up as quickly as you can.
Assume a pushup position with your arms straight. Lift your right foot off the floor and bring your knee as close to your chest as you can, touching the floor with your toes. Repeat with your left leg. Continue alternating back and forth.