Sex as exercise
» Sexual Wellbeing
Erotic Exercise Even though sex probably involves less energy expenditure than most aerobic exercise, it can give you a workout, depending upon how vigorous it is. After all, sex, and particularly orgasm, involves the contraction of muscles in the arms, legs and abdomen. Also, your heart and breathing rates rise when you are sexually aroused just as they do when you exert yourself on the playing field or at the gym. Another bonus is that you're likely to drift off into a deep, luxurious sleep after you tire yourself out.
Health, Good Vibrations: Uncovering the Health Benefits of Sex