Shadow boxing only gets you so far. Start mastering the techniques and only then work on power. Come home and cap of the day with a perfect boxing work-out with your punching bag. Practice makes perfect. Master delivering your roundhouse kicks with speed and precision. Your kick bag will be with you for many drills to come. Start kicking slowly and around kick 100 reach full power. One. One. One. Two. One. Each hit and your bag flies back at you. Practice boxing and other martial arts. Take out all your pent-up rage at the bag rather than your co-workers. Fill you boxing bag base with sand or water. Unleash your fury knowing your punching bag will stay upright. No sliding around. The suction cups keep in firmly in place. Follow the instructions and you will quickly have your new heavy punching bag. Heavier per volume and will always remain hygienic.