Pendragon is a boxing-based upper body strength workout that uses concentric and eccentric muscle movements to load upper body muscle groups and deliver results fast. While this is not designed to stress your VO2 Max it will get you in the sweatzone quickly. Make sure your form is perfect and you have perfected your punching, pivoting on the foot that's on the same side as the arm you're punching with so that your bodyweight shifts behind the punch.