It is normal for men to have sex or masturbate once every 4 days. As long as it does not affect the sexual harmony between partners, there is nothing wrong with it. The number of days a man has sex varies from person to person and can be affected by age, physical condition, endocrine hormones, mental state, etc. Under normal circumstances, the majority of men between 20 and 30 years old, 1-2 days to have sex once is relatively normal; 30-40 years old men, usually 3-4 days to have sex once; and 40-50 years old men, a week to have sex once is also relatively normal. As long as there is no obvious fatigue, or poor mental state the next day after sex, and does not affect normal life and work, it is normal.