Sex Burns Calories

Thirty minutes of sex burns 85 calories or more. It may not sound like much, but it adds up: 42 half-hour sessions will burn 3,570 calories, more than enough to lose a pound. Doubling up, you could drop that pound in 21 hour-long sessions.

"Sex is a great mode of exercise," says Patti Britton, PhD, a Los Angeles sexologist and president of the American Association of Sexuality Educators and Therapists. It takes work, from both a physical and psychological perspective, to do it well, she says.

Sex Boosts Immunity

Good sexual health may mean better physical health. Having sex once or twice a week has been linked with higher levels of an antibody, which can protect you from getting colds and other infections.

Sex Relieves Stress

A big health benefit of sex is lower blood pressure and overall stress reduction, according to researchers from Scotland who reported their findings in the journal Biological Psychology. They studied 24 women and 22 men who kept records of their sexual activity. Then the researchers subjected them to stressful situations -- such as speaking in public and doing verbal arithmetic -- and noted their blood pressure response to stress.

Those who had intercourse had better responses to stress than those who engaged in other sexual behaviors or abstained.

Another study published in the same journal found that frequent intercourse was associated with lower diastolic blood pressure in cohabiting participants. Yet other research found a link between partner hugs and lower blood pressure in women