When you’re crawling under the covers tonight, should you think twice about putting on your favorite pajamas?
A National Sleep Foundation poll reports that 12% of Americans sleep au naturel and studies are mixed on whether what you wear to bed matters. We waded through the research to provide some answers on the supposed benefits of sleeping in the buff.
… Improve Your Relationship
For couples, sleeping naked could increase relationship satisfaction. A survey of more than 1,000 adults found 57% of those who slept naked felt happy in their relationships (compared with 48% who wore pajamas).
“If you and partner both sleep naked, the skin-to-skin contact will release the feel-good hormone [oxytocin],” says Fran Walfish, PsyD, a Beverly Hills, California-based relationship psychotherapist.
Research shows even non-sexual contact with the skin boosts levels of oxytocin. The hormone, also released during sex, is associated with lower levels of depression, stress and reduced blood pressure.
… Improve Your Sleep
Feeling overheated makes it harder to get a good night’s rest. Researchers at the University of Amsterdam found increasing skin temperature just 0.4º Celsius was linked with worsened insomnia and increased nighttime waking.
“You do sleep better if you’re cooler,” explains Dr. Daniel Root, a sleep specialist and medical director at Oregon Sleep Associates.
But layers are important to prevent heat loss, so Root suggests having an extra blanket on the bed in case you catch a chill. Performance sleepwear and sheets made of breathable, moisture-wicking fabrics can also help regulate your body temperature.
… Preserve Sperm Quality
In a 2015 study, researchers tracked 501 couples for 12 months to assess links between underwear choice and sperm quality. The data showed men who wore boxers during the day and slept naked had better overall sperm quality and higher fertility than those who chose tighter-fitting underwear, like briefs.
The connection relates to temperature, notes Root. When the testicles are too warm, it’s harder to make good sperm. Sleeping in briefs, he notes, keeps the testicles snug against the body, increasing the temperature. Sleeping naked — or wearing boxers — gives testicles more room to move, thus improving sperm quality.
… Lead to Insomnia
Stripping down to avoid overheating could help you get more restful sleep or it could cause you to wake-up repeatedly during the night. It all comes down to temperature. Research found that men who slept in cold temperatures spent more time awake and less time in stage 2 sleep, the stage associated with lowered core body temperature. Results were similar in research done on women: Cold stress impaired sleep and led to less time spent in stage 3 (slow wave) sleep, the cycle associated with drifting into a deep sleep.
The takeaway, according to Root: Sleep naked or wear pajamas.
“The most important thing is being comfortable physically and psychologically when you go to bed so wear [or don’t wear] whatever works for you,” he says.