Forty-year-old men how long a sex life appropriate can not be generalized, need to be combined with the individual’s physical condition for a comprehensive judgment. Under normal circumstances, forty-year-old men how long to have a sex life, there is no strict limit and standard, the specific frequency of sex life can be based on the conscious symptoms of both men and women after sex to choose, as long as each sex life can keep the spirit of pleasure, no waist and knee soreness, mental discomfort and other uncomfortable symptoms. There are also foreign scholars believe that forty-year-old men, every five days a sex life is appropriate, but if discomfort in the process, need to properly reduce the frequency of sex life. So forty-year-old men how long a suitable sex life varies from person to person, and moderate and harmonious sex life, not only can promote the emotions of both husband and wife, but also can make people physically and mentally relaxed, beneficial to health, life and work are beneficial.