This is Romero’s go-to exercise. “It’s the ultimate calorie-burn,” she says. Burpees are basically squat thrusts; they increase both your muscular and cardiovascular endurance at the same time. Burpees are recommended for building total-body strength and power, as well as for developing functional strength and improving your aerobic fitness. This exercise also has the advantage of effectively developing your core strength and joint range of motion.