Miranda Levy
Dr Kristen Holmes is a psycho-physiologist who specialises in sleep and training recovery. She is the global head of human performance and principal scientist at healthspan company Whoop.
Insomnia is a creation of modern life: the everyday rat race has dragged us away from the primal cycles of nature by which our ancestors lived. We wake up to the sound of alarms rather than natural light, while long working hours mean we go to bed much later than we should. As a result, our biological rhythms become disrupted, and this can have an impact on our innate drives for both sleep and sex.
Sex, like sleep, is a health-promoting behaviour. In fact, one study found wearers of a fitness tracker ring who reported having sex the previous day saw 11.7 per cent more deep sleep (the type that is most restorative) and 2.4 per cent more total sleep than those who didn’t report having sex.
When you are in a safe, loving relationship, sex creates a bond and connection which leads to the production of positive hormones which then help to lull you to a restful sleep. In some ways, sex is similar to alcohol in that “one drink” can loosen you up, creating the conditions for intimacy and relaxation. This can be harder to achieve without intercourse – but not impossible.
From arousal to orgasm, humans release a coordinated mix of neurochemicals which lead to pleasure, bonding and feelings of trust. These peak when we have a sexual climax.
The first of these is oxytocin, the “love hormone” (it’s the same chemical that women release when they are breastfeeding to bond with their child) which you release when you are intimate with a partner. Oxytocin lowers the stress hormone, cortisol, creating the mechanism for you to fall asleep.
At the same time, a neurotransmitter called serotonin is released, which leads to relaxation and improved mood. At the point of orgasm, both men and women release a hormone called prolactin, which temporarily reduces arousal and prompts a sense of wellbeing and relaxation.
So sex and sleep really are intertwined: the better the sex, the more sleep you’ll get and vice versa.
Men and women aren’t as different as we think
It has become something of a cliché that men fall asleep after orgasm and women stay more alert, but our research does back this up. After orgasm, the body shifts rapidly from a state of high arousal to one dominated by recovery physiology. At the biochemical level, two major post-orgasmic signals come into play: prolactin and oxytocin. Men, on average, experience a higher post-orgasm prolactin spike than women, which helps explain why men typically feel sleepier immediately after sex.
It’s not the same for everyone, however, and post-sex serenity can be influenced by a variety of factors, including the person’s psychological make-up, and how well their relationship is faring. Some women find it easy to fall asleep after orgasm, while many men see sex as a gateway to emotional closeness afterwards.
In good news for women, our data shows that females in particular have a slower resting heart rate the day after they’ve had sex, and they find it easier to drop off the next night. This is because a woman’s heart-rate physiology is influenced by cyclic hormones, which vary depending on where she is in the menstrual cycle. The presence of oestrogen in the female body promotes the “rest and digest” system which leads to calmness, better digestion and a lower heart rate.
Solo versus partner sex
Controlled laboratory studies show that the post-orgasm rise in prolactin is greater after sex than after solo masturbation. This suggests that it’s not only about the climax itself: closeness and cuddling can also help people fall asleep.
However, other studies show that masturbation produces the same neurochemicals as sexual intercourse, particularly in men: in other words, they may fall asleep just as easily after pleasuring themselves.
This could be true for women as well, and perhaps come as little surprise to some since many women don’t orgasm during penetrative sex. A 2024 study published in Brain Sciences found that women had more frequent, more satisfying orgasms on their own, than when they were having intercourse with a partner and this could, in turn, lead to better sleep.
Indeed, a 2025 pilot study, which used a wearable device to measure people’s sleep, found that men and women get better sleep after orgasm, regardless of whether they engaged in partnered or solo sex. In other words, climax probably is the most influential factor in getting good sleep, regardless of how it’s achieved.
Our sex lives don’t necessarily plummet with age
Two years ago, my company performed some research which revealed that, having enjoyed lots of sex in their 20s, many people found their frequency of intercourse dropped in their 30s and 40s but started to rise again in their 50s.
On one level, this might seem surprising. Menopause brings a systemic decline in the production of oestrogen and androgen, which has well documented effects on sexual physiology. Oestrogen loss leads to thinning and reduced elasticity of vaginal tissues and decreased lubrication, which can make intercourse less comfortable and dampen desire.
Men also experience hormonal changes: a gradual, natural decline in testosterone levels starting around age 30 to 40 which can also affect their sex drive, though a recent study found that despite the drop in testosterone, men’s libidos in fact peak around the age of 40, possibly as a result of contextual factors such as being in a stable relationship.
Women can also have a decline in testosterone, though less it’s dramatic than in men, also contributing to a lower libido. Hormone replacement therapy can address these changes. Such transitions can be exacerbated by stress, a worsening body image, and relationship difficulties. That said, not all women experience reduced desire.
Some report unchanged or even increased sexual interest post-menopause, often due to reduced fear of unintended pregnancy, and enjoying more freedom to pursue intimacy after the children have left home. It is a nuanced discussion and needs further study to really understand what happens to our sex drives as we age.
Four ways to improve your sleep and sex life – tonight
It doesn’t matter if you can’t do all these things, all, every day. Try and stick to the 80/20 rule, where you manage to do most of them, 80 per cent of the time.
1. Set your alarm for the same time every day
Dopamine, the “pleasure and reward” neurotransmitter which reinforces desire and motivation, is greatly affected by the brain’s exposure to light. A 2017 review published in Translational Psychiatry revealed that, when people received light exposure during the biological night (ie, between 10pm and 4am) their dopamine production was impaired, they slept less well, and hence their libido went down.
The first thing to do every morning is to get your “light diet” under control. Wake up before 8am, and go outside: even if it’s a cloudy winter day, it doesn’t matter. This will allow your body to understand what time of day it is. It’ll add a huge boost to your general health, and it doesn’t cost anything.
2. At the end of the day, prepare your brain for sleep
After the sun goes down, it’s time to tell your body to calm itself. So, this means protecting your brain from blue light from overhead lamps, laptop screens and mobile phones. Shutting down your tech will support the release of melatonin, the hormone that helps you feel sleepy, and gives you some time to be present with your partner.
Follow the protocol of waking up at a similar time and viewing bright light and you will begin to feel naturally sleepy around the same time each day.
3. Restrict your eating to within a 12-hour window
Many people end up snacking across a long daily window, often 15 hours or more, which keeps their metabolism and hormone signals running constantly instead of letting them rest and reset.
Eating over such an extended period can also disrupt your normal circadian and metabolic function, leading to increased physiological “stress” on the body. When your internal rhythms are misaligned in this way, it’s not surprising that overall well-being – including libido and hormonal balance – can suffer.
4. Do some exercise every day
Our data show that people sleep for longer periods, and more deeply, if they do regular physical activity. Exercise can help regulate your circadian rhythm, reduce stress, and enhance the physical and mental recovery processes that support more restorative sleep.
Physical fitness also supports your libido through improving your blood flow, hormone balance, and mood, all of which help sustain sexual desire and performance.
As told to Miranda Levy
Telegraph UK
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