According to a recent studies having regular sex can help promote positive emotional well being, reduce headaches and even lower the risk of prostate cancer. A Canadian study last month found that 30 minutes of sexual activity can burn more calories than when you are on a treadmill. It isn't just the heart and lungs that get a good workout either, during other studies it shows that brain cells increase after having sex. It is important to note however that you must keep at it and make it a habit rather than one off occasions for health benefits to be noticed.
So now there really is no excuse to have sex daily, to increase your health, stick at it ;)