While society has changed for the better with more equality than ever between the sexes, some biological differences are still present - some in areas that may surprise you, one of which is sleep.
A Royal Society of Medicine conference this month in London presented many scientific hypotheses regarding differences in sleep between genders, including that women sleep more than men, tend to be better in the morning, but are more likely to suffer the consequences of poor sleep.
Men on the other hand have been found to get less restorative, deep sleep than women, are more likely to be night owls and are at a greater risk of some sleep disorders like sleep apnoea.
Dr Helen Driver, a sleep specialist at Kingston General Hospital and Queen's University in Canada said at the conference: "While the basic principles of sleep are the same in men and women — we all sleep in about 90-minute cycles, deeply in the first part of the night and recover from sleep loss by having more deep sleep — there is growing evidence of subtle differences between men and women,"
"Understanding the differences in the way men and women sleep is an emerging area of medicine. As we understand it better, it could lead to tailored treatments to help ensure that, whatever your gender, you can get a good night’s sleep," she said.
So what are the differences?
Men get less restorative sleep
The body repairs itself during the deep sleep stage of non-REM (rapid eye movement) sleep. This equates to about 20% of your total sleep.
During this time, the brainwaves are much slower and the growth hormone is released. The body uses this to repair and regrow tissues, build bones and muscle, and strengthen the immune system.
"This deep sleep declines with age, but it decreases earlier in men — starting in their 20s and 30s —while it is a decade later in women. It is unclear why, but one theory is that growth hormone production decreases earlier in men. This means women tend to get more of this “quality” sleep," says Dr Driver.
Women are more at risk of insomnia
It may make sense then that women are more prone to insomnia, because are getting more restorative sleep - they are about 50% more likely than men to experience insomnia. This may be contributed to by women being more likely to "ruminate and worry", making their mind unable to settle according to Dr. Driver.
Biological differences may also contribute:
"Period pain can cause women to have disturbed sleep, and fluctuating hormone levels across the menstrual cycle cause subtle changes in sleep. Pregnant women’s sleep can be disturbed by restless leg syndrome, needing to go to the loo more frequently and difficulty getting comfortable," says Driver.
Also, during the menopause, women’s sleep can be disturbed by hot flushes which can wake them as their body temperature rises.
Men tend to snore more
After ovulation and before menstruation, a woman’s levels of the hormone progesterone rise. It interacts with receptors in the brain that respond to GABA, an amino acid that helps the body relax. The effect is to act as a bit of a sedative, helping women to sleep, says Dr Driver.
"It also has a protective effect on respiration, helping with breathing,’ she adds. This means that, before the menopause, women are less likely to suffer from sleep apnoea (where the walls of the airway narrow, causing pauses in breathing) than men. The brain prompts the body to breathe again and a rush of air through the collapsed tissues causes snoring. Even if women suffer from sleep apnoea, the airway tends to narrow rather than close. However, this tends to mean they have a longer time with a narrowed airway during deep sleep and wake as a result," says Dr. Driver.
A new survey by the Royal National Throat, Nose and Ear Hospital recently found that the number of young women snoring was higher than men though. Experts say this rise could be due to a number of factors, including rising obesity levels and increased alcohol consumtion among women.
Women suffer more from lack of sleep
Growing evidence suggests that women are more susceptible than men to the impact of sleep debt, including high blood pressure and cardiovascular issues.
A study conducted by New York's Columbia University last year looked at the link between blood pressure and sleep, and found that people who took longer to fall asleep and had poorer sleep quality were more likely to have high blood pressure.
Researchers believe even mild sleep issues may trigger inflammation of the blood vessels that can contribute to cardiovascular disease.
Another study back in 2008 by Duke University found that poor sleep has more serious health consequences for women, as its more likely to cause psychological distress and higher levels of biomarkers associated with elevated risk of heart disease and type 2 diabetes.
Men sleep for 20 minutes less than women on average
Many studies have found that women are more likely to be early risers, while men are more likely to be night owls. Its also been found that women go to bed earlier and sleep slightly longer on average.
In a 2016 study by Professir Jim Horne of Loughborough University, found that women get 20 minutes more sleep than men on average. He suggests this is due to women's multi-tasking brains.
The theory is that the more of your brain you use during the day, the more sleep it needs to recover. Men who have complex jobs that involve lots of lateral thinking and decision-making will also likely need more sleep Horne says.
"Multi-tasking might be a good thing, says Professor Horne. ‘The more you use your brain, the more deep sleep you will have. We know that women’s brains age more slowly than men’s; a woman’s brain at 75 is the same as a man’s at 70. However, we don’t yet know what role sleep plays in the ageing of the brain."
Will stay-at-home dads sleep more like women?
With changes in society and traditionaly gender roles though, maybe men and women's sleep styles will change:
‘Historically, women have had more “on-call” sleep — sleep that is regularly disrupted as they get up to look after children,’ says Dr Driver. ‘This can cause hyperarousal — when the body kicks into a state‘Historically, women have had more “on-call” sleep — sleep that is regularly disrupted as they get up to look after children,’ says Dr Driver. ‘This can cause hyperarousal — when the body kicks into a state of high alert — causing the mind to race and insomnia. of high alert — causing the mind to race and insomnia.
"Historically, women have had more 'on-call' sleep — sleep that is regularly disrupted as they get up to look after children. This can cause hyperarousal — when the body kicks into a state of high alert — causing the mind to race and insomnia. Childcare responsibilities are increasingly being shared between both sexes. It will be interesting to see whether this alters sleeping patterns. Will our bodies adapt to social changes?" asks Dr Driver.
And with that, we're off to take a well earned nap.