So what's he thinking? Well Sklar has adapted the classic boxing punch rotation routine to turn the bottles into makeshift weights.
Begin with your feet just outside hips-width, gripping the bottles with your palms facing down. By squeezing your lower body and core, you'll create tension throughout your body.
Get into a guard position – your hands in front of your chest at shoulder height. While your feet are planted, rotate your torso as you punch one arm at a time – maintaining shoulder height.
Increase the speed to get a greater workout while insuring your hips don't rotate. Aim for 20 reps.
Next, without taking a rest and dropping your ams, crank out another 20 reps but this time punching at eye-heigh.
Go for 10 sets, with 30 second breaks between. Try and keep that intensity up the entire way through.