“Saving yourself" before a big game, or the big business deal, may indeed confer some moral benefit. But corporeally it does absolutely zip. There's no evidence that lack of sex sharpens your competitive edge. Having regular and enthusiastic sex, confers a host of measurable physiological advantages, be you male or female. (This assumes that you are engaging in safe and protected sex.)

In one of the most credible studies correlating overall health with sexual frequency, Queens University in Belfast tracked the mortality of about 1,000 middle-aged men over the course of a decade. The study was designed to compare persons of comparable circumstances, age and health. Its findings, published in 1997 in the British Medical Journal, were that men who reported the highest frequency of orgasm enjoyed a death rate half that of the laggards. Other studies (some rigorous, some less so) purport to show that having sex even a few times a week has an associative or causal relationship with the following:

- Improved sense of smell: After sex, production of the hormone prolactin surges. This in turn causes stem cells in the brain to develop new neurons in the brain's olfactory bulb, its smell center.

- Reduced risk of heart disease: In a 2001 follow-up to the Queens University study mentioned above, researchers focused on cardiovascular health. Their finding? That by having sex three or more times a week, men reduced their risk of heart attack or stroke by half. In reporting these results, the co-author of the study, Shah Ebrahim, Ph.D., displayed the well-loved British gift for understatement: "The relationship found between frequency of sexual intercourse and mortality is of considerable public interest."

- Weight loss, and overall fitness: Sex, if nothing else, is exercise. A vigorous encounter burns some 200 calories is about the same as running 15 minutes on a treadmill or playing a spirited game of squash. The pulse rate, in a person aroused, rises from about 70 beats per minute to 150, the same as that of an athlete putting forth maximum effort. British researchers have determined that the equivalent of six Big Macs can be worked off by having sex three times a week for a year. Muscular contractions during intercourse work the pelvis, thighs, buttocks, arms, neck and thorax. Sex also boosts production of testosterone, which leads to stronger bones and muscles. Researchers have gone so far as to call the bed the single greatest piece of exercise equipment ever invented!

- Pain-relief: Immediately before orgasm, levels of the hormone oxytocin surge to five times their normal level. This in turn releases endorphin, which alleviates the pain of everything from headaches to arthritis to even migraines. In women, sex also prompts production of estrogen, which can reduce the pain of PMS.

- Less-frequent colds and flu: Wilkes University in Pennsylvania says individuals who have sex once or twice a week show 30% higher levels of an antibody called immunoglobulin A, which is known to boost the immune system.

- Better bladder control: Heard of Kegel exercises? You do them, whether you know it or not, every time you stem your flow of urine. The same set of muscles is worked during sex.

- A Healthier Prostate: Some urologists believe they see a relationship between the infrequency of ejaculation and cancer of the prostate. The causal argument goes like this: To produce seminal fluid, the prostate and the seminal vesicles take such substances from the blood as zinc, citric acid and potassium, then concentrate them up to 600 times. Any carcinogens present in the blood likewise would be con-centrated. Rather than have concentrated carcinogens hanging around causing trouble, it's better to evict them. Regular old sex could do the job. But if the flushing of the prostate were your only objective, masturbation might be a better way to go, especially for the non-monogamous male.