Clearly, you need some added incentive. How about this? Regular cardiovascular exercise will improve your sex life.

Before you grab your butt-floss spandex and Olivia "Let’s Get Physical" Newton John sweatband on that info alone, consider this: A University of California study reported that a group of sedentary middle-aged men made love 30 per cent more often and masturbated 50 per cent more often after nine months of regular workouts.

Exercise not only relieves stress, relaxes you, increases your energy and stamina, and improves self-esteem and self-confidence (all very sex-positive), working yourself into a big, smelly sweat actually also makes you horny. Cardiovascular exercise elevates endorphins in your bloodstream and increases adrenaline and testosterone (in women too)–all the things your brain needs to make you want to say "Do me!"

There are other sex-specific benefits from exercise.

For women, regular exercise keeps your muff nice and fit. Like other muscles in your body, the ones around your vagina get flabby with age, allowing you to enjoy the pleasures of incontinence or a condition known as prolapse, when your womb gets lazy and slumps down toward your vaginal canal. Keeping fit also helps keep the juices flowing as you age, which not only makes sex a lot more fun but also protects you from infection.

Fitness aids sex, sex aids fitness

And guys, you’re not always going to be the studly young things you are now. In a chapter called "Drop Your Lard and Get Truly Get Hard" in the book Sex: A Man’s Guide, it says that men’s levels of arousal and their ability to maintain erections wane as you age. Regular exercise helps avoid this.

And a good set of butt and lower back muscles just might stop that shaky feeling like you’re about to collapse when you’re doing the nasty. Abs of steel (or at least aluminium), strong thighs, and a decent set of shoulders don’t hurt either, and that goes for men and women.

Sex itself is a good workout. Most cardiovascular fitness routines recommend that to get and keep fit you need to raise your pulse and keep it an increased rate for 20 minutes, two or three times a week. So if you can’t afford a gym membership...

An enthusiastic session of sex (the kind that leaves your legs rubbery and your head light), multiplies your heart rate as much as three times and you can burn up to 300 calories. And a good, toe-curling orgasm helps tone every muscle in your body.

Exercising together is a big turn-on. Getting hot and sweaty with your partner can be great foreplay. And keeping your balance while doing in the shower together afterward will help keep you fit.

You don’t even need to go to the gym. Some of the best sex I ever had–with a guy who was otherwise a bore in bed–was after a good naked wrestling match. Crawling over the equipment in a kids’ playground and then crawling all over each other can be a lot of fun and a good work-out, too. Even romantic walks together are a great way to get some exercise and get turned on.

Of course, one of the main reasons we work out is vanity. We want to look hot. And there’s no denying the appeal of a fit body.

Pump up your body confidence

I’m not talking beefcake–I like my men with necks. But someone who looks like he takes care of his body, no matter what his body type, is a big turn-on. People are drawn to you–and you to them–when you feel good about yourself physically. Just keep in mind, there’s no bigger turn-off than someone who’s too caught up with their image and the shape of their body.

Also, I know it’s tempting to nag if you think there’s something your partner should do about their physical appearance. But a critical glance as the tubby love of your life reaches for a second helping of Double Fudge Brownie Delight will likely only lead to you wearing it in your lap.

The best way to make your partner feel like you love his or her body is to send out a steady message of acceptance. We tend to slow down the compliments as we get more comfy, when they’re really most important. No need to lie. Just focus on things you genuinely like and mention them often.

Of course, relying too much on your partner to reassure you is annoying if you do nothing to accept yourself. A girlfriend said she really noticed the difference when she stopped being so self-conscious about her body, and started parading around in the buff not making any effort to avoid bad lighting or rear views. It made her feel great, and the men she was with found her body confidence extremely sexy.

And remember, just because guys don’t sit around and whine to each other about their saggy bits ("Oh God, Doug, I just hate my gut." "Oh c’mon Steve, you look great!") doesn’t mean body image isn’t an issue for them. Be nice.

Now if you’ll excuse me, I’m off to the bedroom for a little 20-minute workout.