What can pull-ups do to enhance physical fitness? When is the best time of day? How many days will there be obvious muscles?

People with weak physique should strengthen their physique from aerobic exercise (such as running, basketball and badminton). Pull-ups are an action to exercise muscles and back muscles. Muscle exercise needs scientific planning and exercise, supplemented by diet. The exercise effect is usually in years, but after training, some changes in physical fitness can be seen within a few months. It is impossible to become a muscular man at once. Exercise time is suggested to be from 4 pm to 6 pm or one or two hours after dinner to one or two hours before going to bed. Hope to adopt