Exercise time is generally evaluated by three indicators: net exercise time, time period and body reaction cycle.
Net exercise time refers to the time of pure exercise state, such as continuous exercise time, or exercise time except rest in intermittent exercise. Time period refers to intermittent sports (intermittent rest in continuous sports), such as table tennis and badminton, in which 30 minutes is a time period. The body response cycle is based on the body response. Exercise causes some reactions in the body, such as fever, facial flushing, stretching of the whole body joints, slight sweating in the front, heart and back, slight fatigue, obvious feeling of rapid heartbeat, deepening and accelerating breathing, etc. The time from the beginning of exercise to the body reaction reaching the above level is a body reaction cycle.
To achieve a certain fitness effect, the exercise time is generally based on the net exercise time of 30 ~ 45 minutes, or 1 ~ 2 time periods (30 ~ 60 minutes), or 1 ~ 2 physical reaction cycles. A healthy person with basic exercise and good physical function can exercise for 2-3 exercise cycles (60-90 minutes) or 2-3 body reaction cycles, and the net exercise time can also exceed 45 minutes to 60 minutes. The rehabilitation exercise time of patients with weak constitution and chronic diseases can be adjusted appropriately, and it is better to complete the net exercise time of 20-30 minutes, or an exercise cycle (30 minutes), or a physical reaction cycle. You can also exercise several times in a short time, such as exercising 10 ~ 15 minutes, resting for 5 ~ 10 minutes, and then continuing to exercise 10 ~ 15 minutes.