Sex and Running: Is sex a new workout you should add to your weekly schedule? NO.

It is a truth universally disavowed that sport is all about sex. We prefer to think that there is some higher goal, but it is really an exercise in showing off and, later on, taking off. No sooner does a football match end these days than Cristiano Ronaldo is removing his shirt and smouldering into the camera with the air of a man for whom 4-4-2 holds only limited fascination.

Boxers, by nature, are poseurs. Athletes wear dental floss. Racing drivers are just classier versions of little boys driving around in Fiestas; when Lewis Hamilton won the Formula One world title he was only several steps removed from the teenager boasting about his new alloy wheels and stereo surround.

I have no problem with this. Sport is basically a nation's youth hooked up to a testosterone drip. I still recall the day I saw Maria Sharapova walk into the media centre at Wimbledon and a phalanx of middle-aged men disappeared down a whirlpool of their own dribble. In their defence, she could hardly complain given that she had spent that afternoon flashing her knickers and grunting like a rutting wildebeest in the name of being taking seriously.

I was also told recently by a football agent that a Premiership player had got himself into fantastic physical shape. I remarked how good it was to hear of a young man taking his job seriously. The agent then pointed out the regime was undertaken strictly with a view to looking good when he got his latest groupie into the penthouse suite at the Hilton. Anything else was a bonus.

This is sport. It is sex in socks. But what I find distasteful is the repeated claim by researchers that sex, in itself, is exercise. I resent the claim that sex is good for you and releases endorphins. It irritates me to think I am trawling through purgatory when all I really need is a good bunk-up and a post-match fag.

There are manifold studies (well, who wouldn't want to be a researcher on that one?) that have made wild claims on behalf of the lusty. Queen's University in Belfast announced that you can lose 300 calories an hour by having sex and that sex uses every muscle group in the body, while Dr Graham Jackson of Guy's & St Thomas' Hospital said: "'In fitness terms, its equivalent is going for a mile-long walk."

Clearly, there are flaws in these arguments. For a start, while 300 calories an hour sounds notable, it actually equates to around 30 calories for most of us. That's a cream cracker but I prefer to get cream crackered standing up. I also dispute the idea that sex uses every muscle group as surely this depends on whether you are an apathetic lover or, say, Michael Douglas. The very idea that God has somehow disenfranchised that section of society not given over to bedroom gymnastics and leopardskin negligees also induces a crisis of faith.

But can sex help as part of a running programme? 'Runners' World' has attacked this thorny issue in the past and concluded women marathon runners benefit from having an orgasm the night before a race. Most of the positives are reportedly down to the feel-good hormones released into the brain. It is not known whether faking it achieves the same result, but we do know it will make no difference to her running partner either way.

The magazine editor claimed runners were sex gods and had a positive self-image, thus providing conclusive proof that, despite all the denials and Lycra, I am not a runner. A Canadian cardiologist added: "Running improves vascular health and vascular health is necessary for a male to have a proper sexual function." Again this could be contested by no end of lonely folk for whom a proper sexual function is a pause button.

The sad truth is that running is likely to improve your sex rather than vice-versa. There is no evidence that a French maid outfit will benefit you in the long run, and it is difficult to see how sex can toughen your legs, unless of course you are into S&M.

The entire debate seems confused, which reminds me of Joan Rivers' take on sex education. "I blame my mother for my poor sex life," she recalled. "All she told me was the man goes on top and the woman underneath. For three years my husband and I slept on bunk beds."

The general consensus seems to be that sex is better for women than men before competing in sport. The All Blacks abstained from special cuddles during the 2007 World Cup but were found to be curiously impotent against the Euro love gods of France. Dennis Mitchell, the American athlete, initially escaped a ban after testing positive for heightened levels of testosterone after claiming he had been at it with his wife four times the previous night. "It was her birthday," he protested.

Everyone has an opinion. I even saw one headline that claimed 'Walking Is Better Than Sex'. I thought it was a misprint. We are getting pre-occupied. The fact is sex is not the answer. It's just a good question.