First of all, I may not have mastered the time period. When do you get off work? After a busy day, my muscles are already in a state of considerable fatigue. If the middle exercise time is too long, the fatigue will not decrease, and it will also affect the working state of the next day. Furthermore, aerobic exercise is actually very tiring. It is suggested that 20 to 30 is enough. Otherwise, if you exercise too much, you will be in trouble if your muscles die.