What's better for your health - sleeping naked or in pyjamas?19th Jan 19 | Lifestyle
A doctor tells Prudence Wade if you should ditch your jammies or not.
Sleep: Everyone’s got to do it, and we all have our own rituals to help us get the best rest possible.
Some people just can’t drift off wearing pyjamas – anything but being naked is far too constricting. For others, PJs are a must and they simply can’t snooze feeling exposed.
We all have our personal preferences, but what’s scientifically best? We spoke to Healthspan medical director Dr Sarah Brewer to get to the bottom of it all – and it turns out there really is a clear winner in this particular race.
Quality of sleep
The key difference between sleeping nude and in pyjamas is body temperature. Brewer puts it simply: “You may sleep better naked as your body will remain cooler; overheating is a common cause of disturbed sleep.”
Brewer says people with insomnia have a warmer core body temperature while trying to fall asleep than those who nod off quickly, so if you’re struggling to get to sleep it might be wise to strip off. Not only this, but your body temperature affects the quality of sleep as well. “Being over-hot in bed by three to four degrees changes brain-wave patterns, reduces the amount of time you spend in REM sleep (so you wake up feeling less refreshed), increases awakening and reduces deep sleep,” Brewer explains.
However, as with most things there is a balance to be struck. Brewer says: “Don’t get too cold, as cold exposure will also increase wakefulness.”
Brewer doesn’t think you should have to stop sleeping naked in winter, saying: “If your bedroom is the recommended temperature of between 18 – 24 degrees Celsius all year round, then there shouldn’t be a problem.”
Yeast infections thrive in warm, moist, close spaces – which is why we were so worried about the ladies from Love Island in their thong bikinis this summer.
Brewer says sleeping naked can reduce the risk of fungal skin infections. “By allowing ‘airing’ between the legs, you may benefit from fewer recurrent thrush infections,” she explains – although it’s worth noting that other factors are at play like iron levels, glucose tolerance, stress and general immunity.
“Men can get fungal skin infections in skin creases around their groin, too – commonly known as Jock Strap Itch,” Brewer says. “Keeping the area cool, dry, clean and ‘aired’ at night will help to reduce the overheating that promotes this – especially in summer.”
It might sound like a stretch, but ditching your PJs could actually help your relationship. “Sleeping naked gives a sense of freedom and may help you feel more loving,” Brewer explains. “Humans are highly-tuned to the sight of bare skin which acts as a signal for sexual arousal.”
Science backs this up – just take this research which found that nude bodies were more arousing than clothed bodies and can trigger sexual behaviour.
If you’re too hot in bed, this could actually increase your stress levels and prevent you from waking up well-rested and calm.
“If sleep is disrupted from being too warm, your body produces more cortisol than usual,” Brewer explains. “Cortisol is a stress hormone that is associated with long-term (chronic) stress and puts the body on red alert.”
It’s something of a vicious cycle – if disrupted sleep makes you more stressed, your snooze is likely to be even worse with all the worries whizzing through your head.
Whether you wear PJs or not probably won’t impact a woman’s fertility, but it’s not quite the same for men. If a man is too hot overnight, his sleep might be disturbed, which can affect the secretion of testosterone.
“Sleeping naked may help to promote a healthier sleep pattern so normal testosterone production occurs,” she explains, adding: “More importantly, healthy sperm production needs a cool environment of 32 degrees C – five degrees below normal body temperature (which is why the testes are outside the pelvis). Even a daily soak in a hot bath (43 – 45 degrees C) can lower a man’s sperm count – as can wearing tight, insulated athletic supports.
“Men who wish to father children should avoid hot baths and wear loose, cotton underwear – never tight, polyester pants. They might also consider sleeping naked to stay cooler at night.”
Research shows that overheating at night could impact your skin. We’re by no means saying you’ll definitely overheat and develop a skin condition in pyjamas, but it’s worth keeping in mind that your body temperature will be lower if you’re in the nude.
This study found that people that were too hot by three or four degrees in bed started to sweat more, which could contribute to starting or worsening skin conditions.
© Press Association 2019