According to Aberdeen University hydration expert Dr. John Leiper, approximately nine in 10 adults drink water after jogging or a gym workout, but only four in 10 reach for water after finishing coition. Lovers who don't drink water after making the beast with two backs risk the aftereffects of dehydration, such as waking up tired, with a headache and with a lowered sex drive.

"Most people don't realize that sex is as dehydrating as a session in the gym," Leiper said.

Leiper added that making love for half an hour provides approximately the same physical workout as a three-mile run. "Sweating, flushing and panting are all signs that the heart rate is faster, meaning that the body is reacting in the same way to sex as it does to other cardiovascular exercises," said Leiper. "We continually lose water. When we take part in sex this water loss increases, and we need to continually replace it to prevent dehydration."

The paradox of the French, apparently, extends beyond their reputation for being good lovers (not to mention their ability to drink lots of wine and eat incredibly rich food without experiencing massive obesity and heart problems). They are now also the world's best water drinkers. And these two statistics could be related, Leiper told the Mirror newspaper.