Your muscles are frayed, your lungs ache and your mind is clouded with lust. But you're not having sex yet — just training for it.

A few well-chosen exercises can pump up your love life, experts say. And if you're really smart about it, toning your body can be great foreplay. 

"I think exercising together can be really sexy," says sexologist Dr. Ava Cadell. "If a man does push-ups while his partner is lying underneath, every time he goes down he can kiss her — it's a great motivator. Or, she can do squats over him." 

But if you prefer to keep the preparation and the main event separate, Dr. Barnaby Barratt is your man. 

"We tend to recommend specific exercises that actually assist with arousal and orgasm," says Dr. Barratt, director of the Midwest Institute of Sexology in Detroit. "For women, that means exercises that affect the ability to lubricate and experience excitement in the genitals; for men, anything that improves cardiovascular capacity can increase the ability to have pleasurable erections." 

First, get healthy: Good cardiovascular endurance, muscle tone and flexibility should all be in order well before you reach the bedroom. 

Krazy for Kegels 

But for specific ways to get you ready, the cornerstone of any sexual exercise regimen, Barratt and other experts agree, is the Kegel. 

Contract the muscle you use to stop peeing; now release. It's that simple. 

Named after Dr. Arnold Kegel, who developed the technique in the 1940s, kegeling works the pubococcygeus muscle. Kegels are a near-panacea for maintaining and improving sexual function, especially for women. 

"Kegels prevent a lot of the problems women have as they get older as the sling of muscles in the pelvis start to collapse," Barratt says. 

"In younger women, kegeling improves the flow of blood to the vagina, and for any woman who gets pregnant, it's a way to recover the elasticity of the vaginal canal." 

"For all women," he added, "kegeling improves the quality of orgasmic responsiveness, and intensifies and strengthens orgasmic capacities." 

Translation: Kegels go a long way towards solving sexual problems that have to do with blood flow and muscles, and even if everything is okay downstairs, the exercise can make orgasms easier and stronger. 

For men, Kegels address the two biggest sexual complaints: impotence and premature ejaculation. 

Kegels bring more blood to the genitals, making it easier to get an erection. 

"And they're essential for men who want to control the timing of their ejaculation," Barratt says, since contracting the pubococcygeus can forestall the climax until you're ready — with practice. 

They're easy and covert — do them in the elevator, at the board meeting, at the dinner table and none will be the wiser. But what if you're looking for something a little more intensive? 

Doctor's Orders 

There are some other, more extreme sex exercises out there, Barratt admits. 

"Women can develop the muscles in their genitals," he says. "They actually use little barbells" — which he highly recommends against using without the help of a sex therapist or other doctor. 

Likewise, as men age and their angle of their erection droops, some carefully prescribed exercises can bring things back to the old heights. 

"There's a whole sling of muscles around the testicles and penis shaft that one can exercise," he says, by hanging a dish towel [think coat rack] and flexing. "Keeping those muscles healthy and strong can enhance all sorts of sexual pleasure." Such a regimen should only be done with an expert's advice, he warned. 

The Big Picture 

Once your Kegels have your pubococcygeus as strong as Schwarzenegger's biceps, it's time for the holistic regimen. Exercise in any form will almost certainly help your sex life. 

Researchers at the Harvard School of Public Health found that men who exercise have significantly fewer problems with erectile dysfunction than inactive men. For women, vigorous exercise has been shown to "prime the pump," easing the flow of blood to the genitals. 

"A number of studies have shown that general good health is good for your sex life," said Michelle Gagnon, a personal trainer in San Francisco who created a "Sexercise" workout for the asimba.com Web site. 

"The workout's fairly standard," she said, "based on the premise that you need to be flexible, have good cardiovascular capacity, and be strong enough to hold yourself in various positions." She added that exercise spurs the production of the hormone testosterone, linked directly to libido in both men and women. 

But what does her regimen contain that will really set you apart in the sack? 

"There are a lot of pushups in there," she admitted with a laugh.