Sex does a body - and mind - good. While a romp in the sack may be fun, did you know that it also can benefit your health? We're talking about the kind of sex that happens in committed relationships, of course. Not the ones that begin and end in one evening of carousing. So with your partner, go ahead and get busy because there are plenty of reasons sex gives your health a boost. First, it's a great stress reliever. A Scotland study showed that people who had regular sex responded more favorably to stressful situations than those who abstained, and their blood pressure was lower. Couples who have sex at least once a week have been found to have higher levels of immunity, and for men who had sex twice or more per week, their heart attack rate was reduced by half.