How to exercise penis hardness durability

How to exercise penis durability and hardness? After exercise to improve sexual ability is a certain scientific basis, because moderate health exercise, can improve androgen levels. We advocate exercise for aerobic exercise, such as jogging, swimming, tai chi, in addition to local ability exercise local ability exercise, you can massage the small abdominal acupoints, such as Qihai, Guan Yuan, waterway return, etc., after massage to improve performance.