Chronic diseases have become a major threat to the health of the Chinese people, and insufficient levels of physical activity are one of their main risk factors. In response to this situation, the Bureau of Disease Control of the Ministry of Health issued the Physical Activity Guidelines for Chinese Adults (hereinafter referred to as the Guidelines) to help medical and health professionals guide the general public on physical activity. The five physical activity recommendations in the Guidelines are: ① Perform 6-10,000 equivalent steps per day; ② Perform moderate-intensity aerobic exercise on a regular basis; ③ Actively participate in a variety of sports and recreational activities; ④ Maintain and improve the function of muscles and joints; and ⑤ Be less sedentary and more active in daily life. This article provides a brief explanation of these five recommendations to help readers better understand the content of the Guidelines. Gong Xuejun, Department of General Surgery, Xiangya Hospital, Central South University What is healthy physical activity? The name “physical activity” is derived from the English term “physical activity”, which is defined as muscular activity that increases energy consumption. The term “physical activity” should not be interpreted as activities such as moving your fingers or craning your neck, but rather should emphasize activities that involve large muscle groups and significantly increase energy expenditure, which have been shown to promote health and contribute to the prevention, treatment and rehabilitation of disease. To be precise, the physical activities of medical interest are not all muscular activities that increase energy expenditure, but rather activities that increase the load on the circulatory and respiratory systems, mobilize the metabolism of substances in the body, and improve neuroendocrine regulation, as reflected in the appropriate form, intensity, duration, frequency, and total amount of physical activity. For example, physical activity in daily life can be mopping the floor or walking on the way to and from work, or it can, but does not have to, be a specific physical activity. What is healthful exercise intensity? Exercise intensity refers to the amount of physical or physiological load the body is subjected to for a specified period of time, such as how fast or slow the walking or running speed is. Exercise of different intensities produces different physiological responses and different health effects. Previous scientific evidence and exercise guidelines have emphasized moderate intensity, often represented by brisk walking; as new evidence accumulates, the range of healthful exercise intensities has expanded. The lower limit of moderate intensity has been lowered to the intensity of walking at a moderate speed (4 km/h), and “high intensity” exercise, such as running at a moderate speed, has been recognized as a healthful physical activity because of its greater respiratory, circulatory, and metabolic benefits than moderate-intensity activities. Of course, “high intensity” here does not mean the limit of physical load that the body can withstand, but for individuals, under the premise of moderate amount of strength, to encourage more movement. Is aerobic exercise the only good thing for health? The distinction between aerobic and anaerobic exercise is based on the difference in energy sources, with the former relying on the tricarboxylic acid cycle and the latter relying on the phosphagen system and glycolysis. In our daily life, we do aerobic exercise like walking every day, and at the same time, we cannot do without anaerobic exercise like climbing stairs. The unique value of anaerobic exercise is its ability to promote muscle health more effectively. As the body’s largest organ for sugar storage, fat and sugar breakdown, the functional state of muscle affects the normal metabolic function of the body, and thus its association with the onset, development and prognosis of metabolic syndrome, diabetes mellitus and cardiovascular disease. Muscles can be more effective in increasing and improving their strength and function when they bear larger physical loads and rely mainly on anaerobic pathways to supply energy, which can help prevent or alleviate age-related muscle atrophy. Move for Health, Sedentary for Health Regardless of the intensity or duration, every opportunity should be taken to get the body moving while avoiding sedentary activities as much as possible. This is because, on the one hand, moving increases energy expenditure and helps to maintain a healthy weight; on the other hand, a growing body of research shows that even with 150 minutes of moderate-intensity exercise per week, there is a clear link between sedentary time and the risk of chronic disease and premature death. Therefore, we encourage you to adopt the habit of “less sedentary, more active”, and not to ignore the potential health benefits of a few steps or flights of stairs. Joint flexibility exercises are not necessarily beneficial to health The international academic community, through a systematic review of the health benefits of physical activity, affirmed the role of aerobic exercise and muscle strength exercises, but did not determine that joint flexibility exercises have a role in preventing chronic diseases and premature death. Currently, there are many popular exercise programs in society that focus on joint activities, do not involve large muscle groups, and do not reach moderate intensity, with minimal cardiovascular load and energy expenditure, and limited health benefits if not combined with walking or other moderate-intensity activities that involve large muscle groups. However, some joint activities are easy to perform and can have a significant improvement in symptoms of joint stiffness from sedentary or other static activities. Although most studies have not confirmed their preventive and therapeutic effects on joint disorders, they can help maintain and improve joint function, which is of unique significance for the elderly. The Benefits and Harms of Exercise should be weighed against the benefits and benefits of physical activity, but consideration should also be given to minimizing exercise-induced injuries, including acute cardiovascular events and sports trauma. Two points need to be noted here: first, the content, intensity, duration and frequency of exercise should be selected according to the individual’s exercise capacity, e.g., the moderate intensity of exercise suitable for those in poor health or older age is lower than that for those in good health or younger age; second, changes in the amount of exercise should be gradual so as to give the body a process of acclimatization. Although exercise is one of the triggers of acute cardiovascular events and the occurrence of sudden exercise death is often exaggerated by media reports, its actual incidence is about one in several hundred thousand. However, regular exercise can significantly reduce the overall incidence of cardiovascular events; therefore, the benefits of moderate exercise outweigh the disadvantages. In addition, learning to recognize the precursor symptoms of cardiovascular accidents and making safer arrangements and choices in advance, such as footwear and roads, can help prevent injuries from sports accidents.