Science proves this is the worst exercise for your sexual performance
The theory is simple: get in shape, get more sex. It's pure Darwinism in action.
The grand old bearded theologian Charles Darwin said 'sexual selection' was a core part of the evolution of species.
Without going all David Attenborough on you, the fitter, stronger or more attractive specimens are seen as better breeding partners across the animal kingdom.
Admit it. Most people want to get in better shape to appeal to the opposite sex.
There's no denying that exercise is fantastic for your health, mental well-being, your confidence and how good you look in Speedos on holiday.
But while exercise might help you look like a resplendent peacock to a potential mate, some forms of training could hit your performance in the bedroom, say Eat This Not That.
The male hormone testosterone is crucial to sex drive, sexual performance, and a strong erection. But a study shows that spending too much time running can seriously dent your body's testosterone levels. So that potentially means low libido, erectile dysfunction and fatigue.
Running just under six miles a day was shown to drop your T levels by nearly one fifth, according to the University of British Columbia.
It's not clear the exact effect that hitting the treadmill too hard has on this male sex hormone, but researchers hypothesise that putting in all those miles in training could maybe disrupt communication between your brain and your body's hormone-producing glands.
So if you're training for a marathon or you're a hardcore long distance runner, you might want to ease off. Your testosterone levels naturally peak around the age of 20 and will steadily decline when you hit 30.
But there are ways to naturally boost your T levels and therefore your sex drive. Lifting weight and high intensity exercise are among the best ways to trigger a big testosterone release coursing through your body.
Hitting some heavy metal in the gym is a great muscle builder and burns fat too - but it will spike your testosterone and send your libido soaring.
Getting a good night's sleep, eating healthy fats and things like steak are also good ways to boost that glorious T.