As If You Needed Another Reason

... we have 9!

Yep, 9 reasons to have sex, courtesy of Women's Health. They actually have 18 reasons, but only the first 9 are listed here. I mean, why do you really even need more than 1?

We'll post the other nine, too, but here are the first nine to start:

1. Get more z's. A little sensual massage followed by some dancing in the sheets releases sleep-inducing endorphins.

2. Wake up and smell the roses. Post-romp, you'll experience a surge in the hormone prolactin, which develops new neurons in the brain's olfactory bulb, improving your sense of smell.

3. Watch a Lost DVD marathon without constant bathroom breaks. Sex tones the pelvic muscles that support your uterus, bladder, and bowel, meaning better pee control.

4. No pain, all gain. Right after your big O, you'll be practically swimming in oxytocin (we're talking a seriously intense surge). The overload releases endorphins, which help alleviate pain from arthritis and -- hallelujah! -- menstrual cramps.

5. Put more pep in your step. Rhode Island-based relationship expert Scott Haltzman, M.D., says that women absorb some of the testosterone men secrete in their ejaculate. The payoff: "The increased testosterone can have energy-boosting effects in women."

6. Blow him away in your bikini. According to researchers, regular shagging can tighten your tummy...and firm your bum.

7. Aunt Flow, we meet again. Endocrinologists at Columbia and Stanford universities found that women who have sex at least once a week have more-regular menstrual cycles than those who do it once in a blue moon.

8. Forget flowers and the flat-screen: Sex is an easier (and cheaper) way to make up after a fight.

9. Improve your communication skills. Speaking up about what's working (or not) in the sack can help you express yourself in other parts of your life.