The “lack of exercise” and “muscle starvation” caused by long hours of mental work are mostly manifested in intellectuals. Henry Blackburn said Blackburn once said: “Sitting is the most profound change in human metabolism in the history of civilization, and it is the cause of many of our metabolic disorders”. People who sit for a long time, the lack of physical activity in the end will have what adverse effects on people? 1, physical strength reduced such as: aerobic metabolic capacity (maximum oxygen uptake), anaerobic metabolic capacity, endurance (total body endurance, muscle endurance), muscle strength, energy, agility, adjustment ability. 2, neck, shoulder disease Due to frequent sedentary, ambulatory work or study, the muscles of the neck, shoulders and back are constantly under tension, which affects local blood circulation, insufficient oxygen supply, the waste generated by tissue metabolism can not be eliminated in a timely manner, and accumulate locally, which stimulates the nerve endings in the muscle, resulting in muscle fatigue, soreness, stiffness, and even muscle atrophy in the area. 3, low head syndrome long-term low head ambulation work and study, can make the neck arteries and veins are strained, thus affecting the blood circulation of the brain, can cause dizziness, brain swelling, headache, blurred eyes, vertigo, tinnitus, nausea and other symptoms. 4, cardiovascular disease long-term sedentary, reduced workload of the heart, which can lead to weakened myocardial contraction, heart function. Some data reported that the incidence of coronary heart disease in sedentary people is 12% on average, while long-term manual laborers are 3%. 5, tumor long-term sedentary, can make the gastrointestinal peristalsis slow, resulting in the occurrence of constipation; feces in the intestine stay longer, thus increasing the contact time of harmful substances and intestinal mucosa. In addition, the immunity of sedentary people is weakened, which makes cancer-causing factors easy to invade. Therefore, to prevent and reduce the occurrence of colon and rectal cancer, it is not only necessary to reasonably adjust the diet structure and change the bad lifestyle, but also to insist on participating in physical exercise. Several suggestions: 1. Physical exercise is indeed very necessary, no matter from the characteristics of mental work or from the physiological condition of human body. After working or studying for one hour, get up and do some exercises, such as jogging and hand gymnastics, which can effectively improve physical fitness. 2, ambulatory work or study fatigue, a moderate amount of hand gymnastics can dispel the tension fatigue caused by a high degree of concentration, eliminate local muscle fatigue caused by prolonged sitting, can be carried out neck, shoulder, back muscle exercise. 3, long-term adherence to fitness and hand gymnastics to strengthen the heart muscle and limb muscle strength, strengthen blood circulation, improve the body’s immune system, improve the body’s metabolism, so that the ability to work is greatly enhanced.