Cardio exercise is defined as any exercise that increases the work of the heart and lungs, raising your heart rate. The exercises in this part will get you sweating with a variety of formats including short, incendiary exercises, such as the sprint; multiplanar exercises, such as the cross-country seal; and explosive plyometric exercises, such as the burpee. Check the leveled progression guide for each exercise. If a movement is too simple, try the next level up. If you’re struggling, try the next level down.