Physical exercise may not have a direct relationship with cancer prevention, but it will have an indirect effect. Physical exercise can influence metabolism and affect cardiorespiratory function. Improved metabolism and improved cardiorespiratory function help the immune function of the body. In addition, there are many benefits of physical exercise, including the impact on mood and spirit. Many people have the habit of physical exercise, but once they stop will feel very lost. Because physical exercise can produce beneficial substances, including endorphins in the brain, which are endogenous pleasant hormones, physical exercise can bring pleasant enjoyment or experience, and keep the body and mind in a better state. In addition, physical exercise improves appetite and is beneficial to the gastrointestinal tract. Exercise improves circulation, promotes the secretion of digestive juices, and promotes gastrointestinal peristalsis, the combined effect of which is an overall improvement to the body. Therefore, within the limits of ability, reasonable exercise can improve the prognosis of cancer patients.