7. Mountain Climber
Why it works: Sure you’re gassed from those burpees, but we’re going to stay on the ground and continue pushing the cardio component of the workout with mountain climbers, which develop your hip flexors and abs.
How to do it: This movement mimics mountain climbing. Think of the ground as your mountain. Start in pushup position with the balls of your feet on the ground. Alternate driving your knees forward to their corresponding arm and keep your hips down for the entire motion.
Prescription: 30 reps per side
8. V-Sit Crunch
Why it works: This challenges your abs further after the mountain climbers while giving you a minor breather. Even if your abs are buried deep under that belly, this will help build your core strength.
How to do it: Begin on your back with hands extended over your head. Lift your legs and crunch up at the same time, forming your body into the shape of a “V.” Be sure to lift your legs and trunk simultaneously—doing one ahead of the other makes you lose a lot of the effectiveness of the movement. Exhale as you lift your legs and crunch and inhale as you return to the starting position.
Prescription: 15 reps