The Runner's Witness: Running and the Sweetest Thing

How hard training affects your sex life and vice versa

Shut the door and lock it. Now stand in front of the mirror and slowly take off your clothes. Marvel at your body -- the flatness of your stomach, the curve of your hamstrings. Years of running have made your hips lean and your calves sculpted. You are strong. You are beautiful. You are a runner.

And, fabulous physical specimen that you are, you love sex. Studies have shown that those who exercise have more sex than those who don't. If you're one of those readers who came to the sport later in life, research shows that you made the right decision. A Harvard University study found that athletes in their 40s and 60s had the same amount of sex as non-athletes 20 years younger. And it gets better. Men who run are better able to achieve and maintain an erection, and women who run have an easier time getting aroused and experience more intense orgasms. Anyone feel like a double?

But there can can be too much of a good thing. Numerous studies have shown that the testosterone levels of endurance-trained men are 60 to 85 percent that of their non-endurance-trained counterparts. And although lower testosterone levels can be a protector against heart disease, they can also lower sex drive. Which begs the question: How much is too much?

My informal, unscientific study found that sex did go down as the miles increased, but it was due less to a lack of desire than to fatigue. One happily married couple I know got around the problem by just putting the wife on top. But others said that when mileage reached 110 or 115 miles a week they were just too tired to do anything else. As my friend Jeff put it, "I'm a garden hose for six or seven hours after a 20-miler." Others were so used to high mileage that their desire adjusted. My coach, Kevin McCarey, ran for Athletics West from 1978-82. While he typically ran 125 miles a week during his time in Eugene, it never affected his performance or desire. "When you're 25 years old nothing can stop you," he recalls. "Everyone was so physical. Sex was part of being a runner."

Some argue that the sex/mileage equation has more to do with the relationship than the number of miles. At the start of a relationship, it doesn't matter how far you are running. If your relationship is on the rocks, however, even a taper won't kick your libido into gear. And, of course, in those situations, high mileage can mask real issues between you and your partner.

For a different perspective, I turned to a study from the University of Connecticut that looked at the effect of controlled exercise on animals not known for giving flowers or writing poetry: 2-year-old Morgan stallions. Libido level was measured by the stallion's interest in mounting a breeding dummy. Scores were docked from those stallions particular enough to need an actual mare to achieve an erection. The researchers found that exercised and non-exercised stallions had the same mean libido levels until week 16, and then the libido of exercised stallions started to drop in comparison.

Whether or not running can lower sex drive, some argue that sex can actually improve running. Thirty-five national-caliber age-group runners from San Diego were recently asked whether they would have sex the night before a race: 70 percent said they would. An additional 20 percent said they would have sex the morning of the race, and two reported they would get it on 10 minutes before the start. Presumably, that would be after the warm-up jog and stretching but just before the pre-race striders.

Israeli scientist Alexander Oishanietzky was a vocal proponent of the benefits of sex, saying before the Barcelona Olympics, "Women compete better after orgasm, especially high-jumpers and runners." In an interview after her 1993 U.S. 10K title, Lynn Jennings attributed her win in part to having had sex the night before with her husband. My friend Carol Montgomery, a Canadian Olympian, agrees: "Me, well, anything to keep my mind off the race is a good thing." And for those men who think it is better to abstain, consider that legendary miler Steve Scott believes that sex is an important relaxation technique. "I was always asking to have sex the night before major races," Steve laughs. "But whether I had it or not was out of my control."

So, go ahead. Put on some music; turn down the lights. Don't dwell on how far you ran this morning, or how fast you have to run tomorrow. After all, isn't sex at least one of the reasons you run?

Former public defender and current Ph.D. student Tamara Lave was an All-American at Haverford College and represented the U.S. in the marathon at the 2003 IAAF World Track and Field Championships in Paris.