People who work hard for a long time are generally stronger. This is because some parts of the tissues and organs have been exercised during exercise, so they are more developed. Heart activity will also increase. The premise is that physical strength is not brain power. However, due to the limitation of work characteristics and production and labor methods, the body can only have one or several muscle groups, which makes it easy to feel tired. If we can't properly combine sports activities with rest adjustment, some diseases will occur.
For example, long-term monotonous bending action is easy to make back muscles tired and sacrospinous muscles injured, which is commonly called lumbar muscle strain. Some jobs need to stand for a long time, which leads to venous blood reflux of lower limbs and easily leads to varicose veins of lower limbs. Work that requires sitting for a long time will increase abdominal pressure and cause diseases such as indigestion. Physical exercise can exercise muscles in all parts of the human body, such as muscle fibers becoming thicker and stronger; Can enhance myocardial contractility and improve vascular elasticity; Can increase vital capacity; Can make the nervous system more flexible and responsive.