1. Regarding the exercise frequency, the American Sports Medicine Association recommends that normal people exercise 2-5 times a week. If they have no exercise habits before, start small, twice a week, and then gradually increase to three or four times. Beginners often make the mistake of exercising once a day because they are enthusiastic and want to achieve results as soon as possible, and the intensity of each exercise is also great. Doing so often leads to overtraining, fatigue, insomnia, excessive soreness and other symptoms in a short time. And then it will stop. In fact, we should realize that fitness is a long-term habit. If you want to have a strong body, you should stick to fitness all your life. It takes months or even years to reach the best shape and health. Step by step is the best solution.

Step by step This is the basic principle of all exercises. Exercise intensity should gradually transition from low intensity to medium intensity; The duration should be gradually extended; The number of exercises ranges from less to more. All of the above should be gradually increased within the scope of personal adaptability, so don't rush for success. Old and infirm people or patients with chronic diseases should master the scale of exercise. It's best to see a doctor and have a comprehensive physical examination before exercise. Doctors will prescribe specific aerobic exercise according to individual conditions, and then exercise according to the prescription. In addition, whether the fatigue caused by exercise can be eliminated the next day is also a criterion to measure whether it belongs to aerobic exercise: if the fatigue cannot be eliminated the next day, it means that the exercise is excessive and beyond the scope of aerobic exercise.

3. Aerobic exercise is a kind of persistent exercise to enhance human body's inhalation and utilization of oxygen. Its sports characteristics are light load, strong sense of rhythm and long duration. According to sports medicine, the suitable exercise load of aerobic exercise is 4 ~ 5 times a week, each lasting 20 ~ 30 minutes, and the heart rate during exercise is 120 ~ 135 times/minute. Self-resistance is a muscle strength competition of human muscle groups in static confrontation, and it is also one of the simple aerobic exercises. Not limited by gender, venue and equipment. Free-handed muscle resistance exercise has become a fitness method to accelerate blood flow, promote metabolism and relax muscles and tendons in static training, without worrying about sports injuries. The following are several groups of simple self-resistance exercises in different positions, which can be used as learning exercises.