'Sexercise' yourself into shape
The NHS has some new advice for people struggling to schedule a fitness routine into their daily lives - a workout between the sheets.
According to the NHS Direct website, "sexercise" can lower the risk of heart attacks and helps people live longer.
Endorphins released during orgasm stimulate immune system cells, which also helps target illnesses like cancer, as well as wrinkles, it states.
Sexual health experts said such claims could not be scientifically proven.
"It's good to see the NHS are promoting sexual wellbeing," Dr Melissa Sayer told the Guardian newspaper.
"Yes, there is evidence that sex has benefits for mental wellbeing, but to say there is a link with reduced risk of heart disease and cancer is taking the argument too far."
NHS Direct, however, told the paper the content was "backed by science and clinical evidence" and "isn't just a bit of fun".
The advice, published under the headline "Get more than zeds in bed", is one of several sexual health-related articles to be found on the NHS Direct website.
Sex with a little energy and imagination provides a workout worthy of an athlete, the article says.
"Forget about jogging round the block or struggling with sit-ups.
"Sex uses every muscle group, gets the heart and lungs working hard, and burns about 300 calories an hour."
The advice suggests "regular romps this winter" could lead to a better body and a younger look.
Increased production of endorphins "will make your hair shine and your skin smooth," it adds.
"If you're worried about wrinkles - orgasms even help prevent frown lines from deepening."
The article goes on to say that orgasms release "painkillers" into the bloodstream, which helping keep mild illnesses like colds and aches and pains at bay.
The production of extra oestrogen and testosterone hormones "will keep your bones and muscles healthy, leaving you feeling fabulous inside and out".