*A sandbag is utilized as an opponent body, to be punched and be kicked. It will help to strengthened the bones overall. it will also help to strengthen the muscles. Nowdays, boxing also is a very effective sport tools to relief stress. Throwing a heavy volume of punches at a heavy bag or sand bag will help you develop upper body strength. This is the effective kind of strength that will allow you to throw punches rapidly and absorb upper body punches without getting hurt. Hitting the sand bag is both a strength-building and cardiovascular exercise. Hitting the bag in rapid-fire fashion will help you burn calories at a rate of 400 per hour and develop strength at the same time. It is an effective fat-burning workout. You hit the heavy bag for three to five minutes at a time, take a one-minute break and then repeat the exercise. ***NOTE: The punching bag come with Empty. Feature: *Designed with high-quality material, it is practical and durable. *The punch bag will enhance your endurance, speed and accuracy. *It is a great workout tool for home or gym use. *This target is used for Boxing Sanda (or other martial arts) fans to practice. *The punch bag can be used for punching kicking, martial arts and general fitness. *It can easily withstand long hours of practicing without a problem. Filling Guide: 1. Find the suitable filling material as sugguested below. 2. Sort out internal Sponge layer equaly. 3. Filled up with the material you have prepared, (sugguested first layer filled with old clothes, rags... 4. Use a plastic bag fill up with sand (plastic size should smaller than Sand bag diameter). 5. Insert to middle of sand bag and start filling other material around the sand and untill it full. **DO NOT filled full with sand. it is not the way and too heavy. **Sugguested after fille up, 80cm sand bag around 16KG, and 100cm around 20KG.