Photo by W R from Pexels 1. Boosts Immune System People who have sex have higher levels of what defends your body against germs, viruses, and other intruders. In a study of immunity in people in romantic relationships, people who had frequent sex (one to two times a week) had more immunoglobulin A (IgA) in their saliva. People who had infrequent sex (less than once a week) had significantly less IgA. IgA is the antibody that plays a role in preventing illnesses and is the first line of defense against human papillomavirus, or HPV. But those who had sex more than three times a week had the same amount of IgA as those who had infrequent sex. The study suggests that anxiety and stress can possibly cancel out the positive effects of sex. “Sexually active people take fewer sick days,”   2. Good Appetite People with active sex lives tend to exercise more frequently and have better dietary habits than those who are less sexually active.   3.