After eating generally 1-2 hours to moderate exercise, but as for hitting the back, it takes 3-4 hours to do so. Hitting the back is indeed a traditional health care method, the back has many meridians through, so hitting the back can effectively stimulate the meridians, with the effect of relaxing the tendons and activating the channels. At the same time through the appropriate impact and and vibration, can strengthen the bone strength, to prevent osteoporosis has a certain role. Despite the many benefits of hitting the back, but it is not recommended that the public in a short period of time after a meal to carry out such exercises, because the force hitting the back will not be conducive to the digestion of food, may lead to indigestion, and even too much movement, may cause intestinal torsion, obstruction, etc., but counterproductive. It is not recommended to hit the back immediately after meals and other exercises, should be a little rest 1-2 hours, or even longer after.