We already know that sex can be a decent cardio workout (one 30-minute session can burn 70 calories). Now, research indicates it may protect your heart in other ways.
A study in the Journal of Sex and Marital Therapy found that people who had sex an average of 12 times per month had greater heart rate variability (HRV) -- a measure of how well the heart responds to subtle changes throughout the day (like standing versus sitting).
Higher HRV is a good thing; it may lower your risk of developing heart disease, the leading cause of death for women.
Have sex at least three times a week.
In a study at Scotland's Royal Edinburgh Hospital, people in their 40s who reported having an average of 50 percent more sex than the typical person were judged by a panel of strangers to be about seven to 13 years younger than their actual age.
Researchers believe the youthful glow comes in part from the release of the DHEA hormone during sex. DHEA, which is produced by your adrenal glands, has antiaging properties that can increase the production of collagen and may reduce wrinkles.
Levels of the hormone oxytocin surge after sex, and its stress-reducing qualities may also help you nod off more quickly.
The relationship between shut-eye and intimacy works the other way, too: One study found that women ages 42 to 52 who reported restless sleep patterns were less likely to get physical pleasure from sex than women who regularly got a good night's rest.
If you pass on sex because your head is pounding, you may be missing out on the very thing that could bring relief.
A small study conducted at Southern Illinois University found that nearly half of female migraine sufferers felt better after orgasm.
As endorphins flood the body, they may have an effect similar to morphine, muting your body's pain response and increasing your threshold for discomfort.
A study from Wilkes University in Pennsylvania found that people who had sex once or twice a week enjoyed a boost in their immune system, thanks to a 30 percent increase in immunoglobulin A, the infection-fighting antibody found in the respiratory and gastrointestinal tracts.
Subjects who had sex more than three times a week actually had lower levels of the antibody than those who had less sex.
Researchers believe that in moderation, the release of chemicals during orgasm may enhance your immune function, while too much of these chemicals may suppress it.
For women, quality trumps quantity when it comes to the lifesaving effects of sex.
Simply having positive memories about your sexual past may add roughly four years to your life, according to research at the Duke Center for the Study of Aging and Human Development.
Researchers found that these fond memories may encourage you to continue leading a happier, healthier life.