Making love could be one of the few pleasures in life that is genuinely good for you, say researchers.
Not only does a healthy sex life boost mood, but there is growing evidence to show it boosts your physical well-being, too - from increasing longevity to reducing the risk of erectile dysfunction and even heart attack.
Only last month, researchers at Nottingham University concluded that men who kept up a regular sex life in their 50s were also at lower risk of developing prostate cancer.
(Conversely, they found 'too much' sexual activity - more than 20 times a month - in the 20s and 30s could increase the risk.)
In fact, the research seems to suggest that men - particularly older men - benefit the most from healthy effects of sex. Feel-good hormones help explain some of the benefits, such as mood-boosting, but the explanation is not always obvious.
But one thing is clear, and this applies to both men and women: you need to be having sex regularly if you don't want to lose the ability.
'Use it or lose it' was the advice given to older men by Finnish scientists recently.
They had followed 1,000 men aged between 55 and 75 for five years and found that those who had sex less than once a week at the start of the study were twice as likely to develop erectile dysfunction (see below) as those who had it at least once a week. Those who had sex three or more times a week lowered their risk fourfold.
As women get older their oestrogen levels drop, says Dr Peter Bowen-Simpkins, consultant gynaecologist at the London Women's Clinic and spokesperson for the Royal College of Obstetricians and Gynaecologists.
This hormone is key to a woman's sexual enjoyment - lower levels can make sex uncomfortable, he explains.
But American research found that menopausal women who had sex every week had oestrogen levels twice as high as their abstaining counterparts.