Feed your libido and lose weight? Sounds like a too-good-to-be-true diet, until you really think about it.

Shagging can make you slimmer, if you do enough of it. It can also help the two of you fall for each other all over again. Requiring no monthly fee — dress code optional – you can "sexercise" yourself into shape. This is one gym membership you’ll never want to drop.

Combining sex and fitness is like killing two birds with one stone. Sex gets you fit. And being fit makes you want to have more sex. This is, in large part, because of all of the benefits a good sexercise routine offers, like:

— Improved blood flow in strengthening your heart.

— Better cholesterol, changing more of your bad cholesterol (LDL) to good cholesterol (HDL).

— Weight control.

— Better sleep.

— Greater energy.

— Improved muscle tone and strength.

— Less body fat and lower weight.

— Fewer skin problems, such as rashes and dermatitis.

— Decreased stress.

— Longer life and a better quality of life.

Women, in particular, feel more attractive with sexual fitness, since they produce more estrogen. This makes for shinier, smoother hair. Both sexes glow as their skin pores become cleansed, thanks to sweating. They feel sexier than ever.

Perhaps most exciting for many is the fact that a robust sexercise routine can have you looking one to seven years younger from being happier, better rested, less stressed and more content. And being content goes way beyond general well-being.

Couples who make love regularly feel more passionate for each other. With testosterone levels elevated, they desire more sex. They often have more satisfying sex. Looking better and getting slimmer is cream on the cake. So how do you start this sexercise routine?

Get a physical if you haven’t in a while. While it may be laughable to do this, you’re going to be physically active, accelerating your heart rate, pulse, and blood pressure. You’re also going to be testing and developing your strength, stamina, and flexibility. As with any form of exercise, you need to make sure that you’re good to go.

Aim for half-hour romps 3-5 times a week. This may seem like a lot, but this is actually not very time-consuming. Consider the amount of time you put into your favorite TV show. You’re certainly not losing any weight on the couch with a 6-pack! Go for the other 6-pack!

Remind yourself of the rewards. Sex for 30 minutes burns anywhere from 15-350 calories, depending on how physically active you are. This is the equivalent of calories burned during a half an hour of brisk walking, running, or lifting weights. Vigorous or longer sex sessions five times per week can burn up to 1,650 calories! The active partner — typically the one on top — tends to burn more.

Don’t lose focus. You can easily get distracted with all of sex’s delights. But your goal is to make it burn. In a matter of weeks, you can notice improvements in the tone and strength of your stomach, back, buttocks, legs and arms. But this will only happen if you’re mindful about keeping your heart rate up for a prolonged period of time.

Aim for variety. Your sexercise routine doesn’t have to be routine. You can’t take it for granted that sexercising won’t be boring, at least not in the same way as your treadmill. So get creative. Try new things. As you get in better shape, experiment with sexual positions, like wheelbarrow or crouching tiger. More than anything, make sure that you’re having fun and enjoying yourselves!

Watch what you eat. If you’re seeking to lose weight and tone up, be sensible about your diet. Aim for a well rounded menu of fruits, veggies, dairy, grains and proteins. Limit your carbohydrate intake and your alcohol consumption to a couple of drinks per week. Check out a book, like Kerry McCloskey’s “The Ultimate Sex Diet,” for great recommendations on foods to eat and avoid.

Maintain moderate exercise out of the bedroom. This is still important, especially if you want to be toned, since sexual activity can do only so much. Plus, exercising together is one way to get the two of you in the mood for sex. By releasing endorphins, looking flushed, and feeling alive, regular exercise can be a good form of foreplay.

Take care of each other post-workout. After working up a good sweat, you’ll have to hit the shower. Be sure to do so together, giving each other a well-deserved, after-play rubdown. Nothing can get you more motivated for the next workout than running your wet, soapy hands all over each other’s fitter, finer forms. You may even find that all you needed was a little break.

Dr. Yvonne Kristín Fulbright is a sex educator, relationship expert, columnist and founder of Sexuality Source Inc. She is the author of several books including, "Touch Me There! A Hands-On Guide to Your Orgasmic Hot Spots."

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