The mental and emotional health balance is clearly tuned by sex. People that exhibit involuntary celibate or abstinent often display depressive feelings are often driven into this by 'missed opportunities' due to living without having sex.
Sex eliminates stress. The feeling of total relaxation and calm following sexual intercourse. A subseqent profound caling sleep follows, with great effect in combating stress. With a regular sex life, you'll sleep better and feel better the next day.
Sex helps you live longer. For those who had oragasms more frequently had half the death rate of men who did not have such frequent orgasms. This is due to the plummeting stress hormones, a reaction that installs after we have sex. Frequent orgasms (100 per year) have been linked to an increase of 3-8 years in a person's lifespan and a decrease of death risk of 50%.
Sweating while having sex cleanse the skin pores. Making the skin brigter and decreasing the risk of developing dermatitis.
Sex can keep you fit. A quickie of 20minutes weekly mean 7,500 calories annually, that's as much as you consume on 745 miles of jogging. A sex session can burn about 200 calories. This is like running fifteen minutes on a treadmill.
Sex improves senses, at least the smell. Following the orgasm, a rise of the hormone prolactin makes the brain's stem cells form new neurons in the olfactory bulb, boosting a person's olfactory abilities.
Sex fights off allergies. A good sex session can be a good remedy against stiff nose, being a natural antihistaminic that helps combating asthma and high fever.
Sex means a better control of the bladder, as pelvis muscles controlling the urine flow are stronger.
Also remember use protection! :)