It is normal to have sex once in two days at the age of 40, as long as there is no physical discomfort. There is no uniform standard for “how many days of sex is good”, it varies from person to person. As long as after sex, do not feel fatigue, there is no other discomfort, does not affect the next day’s normal life and work, is normal. Under normal circumstances, 40 years of age, 1 to 2 times a week sex is more appropriate, 6 times in a month can be. But if the libido is more vigorous, you can also appropriately increase the frequency of sex, about 3 times a week. Harmonious sex life will promote the relationship between partners to warm up, help physical and mental health. In addition, usually pay attention to a balanced diet, appropriate exercise to enhance physical fitness, maintain a good state of mind, these not only help physical health, but also help maintain a better state of sexual function.