Do you run on an empty stomach? I think it's because your blood sugar is too low! Anyone who participates in fitness running should pay attention to the law and step by step, especially to control the amount of exercise. In addition, learning "self-control" is particularly important. Because sometimes the desire to run suddenly disappears, it is necessary to distinguish between "unable to run" and "unwilling to run". Of course, if you are sick, you must never run, but in other cases, you should overcome "inertia" and keep exercising. At the beginning of exercise, the speed of running is limited to no uncomfortable feeling, and the distance of running is appropriate to have no hard feeling. Muscle pain in lower limbs may occur after running, which is a normal reaction, and this phenomenon will disappear after a few days of persistent exercise. In order to determine your exercise level, you can do some tests after running for three to four months, and the starting point of calculating the level is 12 minutes. For people aged 30-39, the running distance of 12 minutes is less than 1.5- 1.8 km, which indicates that the sports level is poor. If it can reach 1.8-2.6 km, it means that the sports level is good; If it can exceed 2.6 kilometers, it will reach the excellent sports level. For people aged 40-47, people with poor sports level run within 12 minutes; Ok1.7-2.4km; Excellent over 2.5 kilometers. Poor, good and excellent people over 50 years old run within 12 minutes,10.5 km,10-2.4 km, more than 2.5km ... Don't fantasize about achieving ideal results in a short time, only regular exercise can improve the level of exercise. If you only run once a week, long-distance running will not do you much good. Because in the six days after the interruption of running, the body tissue has consumed all the benefits brought by running. Therefore, run at least three times a week. People who usually lack exercise, once they make up their minds to start regular exercise, often exercise too much, which will lead to bad consequences. Physical exercise should be carried out step by step, and the following items should be recorded in the diary every day: 1, the nature, content, duration and time spent of each exercise; 2. Self-feeling before, during and after exercise; 3. Appetite and sleep status; 4, whether there is a desire to continue to participate in exercise; 5. Pulse is beating. According to the above records, it is not difficult to analyze the amount of exercise and make necessary adjustments to the exercise in time. Generally speaking, the pulse rate should not exceed 120 beats/min after running for 5 minutes and 100 beats/min after running for10 minutes. If the pulse rate is too high, you must reduce the amount of exercise.