The amount of sleep people need is very individualized. But one thing we know for sure: Women need more sleep than men, and when they don't get it, they suffer more.
Not only does sleep deprivation impact women’s health (cardiovascular disease and diabetes rates increase), but athletic performance drops, and metabolic rate is reduced making it harder to lose body fat.
In addition, treatments for sleep disorders appear to be less effective for women than men and sleep becomes a central issue that radically impacts most women’s lives.
The Role Of Hormones
So why do women experience sleep so differently from men?
Hormonal changes throughout a woman’s reproductive cycles affect quality of sleep.
Our ability to sleep is primarily regulated by two interrelated circadian factors: body temperature and hormone levels.
Hormone changes during the menstrual cycle, such as elevated progesterone, affect body temperature, shifting it upward, making women more sensitive to cold. This leads to a reduction in the release of the key sleep hormone, melatonin, reducing sleep quality and quality.
High Cortisol & High Stress
There is some evidence that stress is more detrimental to women. Greater stress means increased release of the hormone cortisol, which, when elevated above normal, keeps you from sleeping well. Normally, you should have a large spike in cortisol first thing in the morning and then experience a gradual decrease to reach low levels in the evening. However, both physical and mental stress will cause cortisol to be elevated all day long, thereby affecting other hormones and the behaviors they regulate.
Because hormones have a domino-like effect, high nighttime cortisol will negatively affect melatonin. When melatonin is inhibited at night, body temperature will stay elevated, making it much harder to go to sleep.
Women Use More Of Their Brains & Need Longer Recovery
Another factor, according to researchers in the UK, is that women tend to use more of their brains during the day because they are juggling multiple responsibilities. This increases the wear and tear on the brain, which can be repaired during deep, rejuvenating sleep.
But that sort of sleep is harder for women to come by: Research shows that women tend to sleep more lightly, wake up more often, and they find it harder to get back to sleep.
The reasons vary: Many women report that their mind’s start racing with all the things on their to-do list for the coming day, and mothers tend to sleep lightly because they are always sensitive to the sound of a child crying. Whatever the reason, women are about 50 percent more likely to suffer a bad night’s sleep at least five days a week than men.
Tired Women Burn Fewer Calories
Most people know that lack of sleep is a major risk factor for obesity. This is because lack of sleep has a huge impact on both metabolic rate and hunger. After just one night of poor sleep, cortisol levels increase in the evening, which contributes to glucose dysregulation, or a worsening of your body’s ability to handle carbs.
A recent study found that when women experienced stressful thoughts and then were given a fat and calorie-packed meal, metabolic rate was reduced such that they burned an average of 104 calories during the 7 hours following the meal compared to women who were more relaxed. The most stressed women had higher levels of insulin, which slows down metabolic rate and causes the body to store fat.
Lack of sleep also makes people feel hungrier and more likely to make poor food choices. Following two nights of sleep restriction, subjects had an 18 percent drop in leptin, a hormone that regulates appetite, and a 28 percent increase in ghrelin, the hormone that triggers hunger. Cravings for salty, high-carb foods increased by 45 percent.
In practice, this translates into an extra 300 calories a day, often from “comfort” foods that exacerbate the problem by stimulating areas of the brain involved in compulsive eating.
Lack Of Sleep = Poor Health
It should be no surprise that lack of sleep negatively affects women’s health in light of how it mucks up hormone balance. When working properly, hormones keep us energized, calm, and level-headed. When they get out of balance, inflammation accumulates, metabolism is degraded, and health is compromised.
A recent large-scale study found that it takes women longer to fall asleep and they have worse sleep quality than men. Trouble sleeping impacted all areas of women’s lives, including mood, metabolic health, and biomarkers associated with disease.
Women with poor sleep quality reported higher levels of hostility, anger, and depression. Researchers suggest that poor sleep leads to dysregulation of at least two systems that lead to depression in women. First, the hypothalamic-pituitary-adrenal axis that regulates stress response gets out of balance. Second, serotonin, which is a calming, feel good neurotransmitter, gets altered. Serotonin is necessary to supply the calm, relaxed feeling necessary for restful sleep.
Trouble sleeping was also closely associated with higher body mass and greater insulin resistance in women, but not men. Finally, inflammatory markers such as IL-6 and C-reactive protein, which are linked to heart disease, were elevated in women who didn’t get sufficient sleep.
Interestingly, scientists report that higher testosterone levels in men blunt the health damaging consequences of bad sleep. Higher testosterone is associated with lower C-reactive protein, greater insulin sensitivity, and less body fat in men.
Don’t Worry—There IS A Solution For Better Sleep
Ladies, you don't need to suffer the misery that comes with chronically poor sleep. There are a number of easy habits you can adopt to start getting all the rest you need:
1: Optimize your light and dark exposure.
Light exposure serves as a key regulator of sleep. When our eyes are exposed to light, melatonin release is halted and body temperature stays elevated, inhibiting sleep. Here are a few habits to adopt:
Eliminate light in your bedroom at night. Get blackout curtains and cover or unplug electronics that emit light.
Avoid TV, cell phone, and other screen exposure for at least an hour before bedtime. Screens emit blue light that decreases melatonin production.
Get bright light exposure first thing in the morning and limit light exposure to dim or amber lights at night. The one possible exception to this advice is in women who suffer from PMS and depression. Research shows that these women have altered circadian hormone release and can benefit from bright light therapy at night
2. Use nutrition to help you sleep.
Pick a meal frequency that allows you to avoid extreme hunger and cravings. If you are having trouble with sleep, avoid fasting or going all day without a solid meal because when you don’t eat, cortisol is unnecessarily elevated.
Eat more protein during the day and carbs at dinner. Protein is a mild simulant for the brain because the amino acids block brain neurons that make you sleepy. This doesn’t mean high-protein diets cause trouble sleeping. They actually improve sleep when people eat their protein during the day and eat carb at dinner.
Eat complex carbs at dinner. Most people enjoy carb foods the most, and eating them is relaxing because they trigger a prolonged insulin release. Try eating complex carbs for dinner, such as sweet potatoes, fruit, or grains.
3: Get your exercise right.
A recent problem for women who love to train is taking exercise too far with chronic long and intense cardio or regular two-a-days. Just like mental stress, this physiological stress increases the likelihood that you’ll experience trouble sleeping due to elevated cortisol and inflammation.
For example, IL-6 is an inflammatory factor, which can improve muscle development at certain levels. However, it can become chronically elevated in response to poor sleep and physical stress, further inhibiting sleep in a cyclical fashion.
On the flipside, a sedentary lifestyle can also lead to poor sleep, though possibly not as radically as too much exercise. There’s not much evidence on how sedentaryism influences circadian rhythms but it’s abysmally bad for health making it reasonable to suggest that if you can’t sleep you need to get active.
4: Try supplements.
Get more magnesium.
Sleep deprivation can deplete your body’s magnesium stores, decreasing your strength and exercise performance. When you sleep poorly, the body produces extra catecholamine hormones to help you get through the day. This causes the excretion of magnesium via the kidneys, resulting in compromised exercise performance and low magnesium.
Shoot for at least 500 mg a day of elemental magnesium, either in your diet or by taking a magnesium that is bound with glycinate or some other form that is easily absorbed by the body.
Get enough vitamin D.
Studies show raising vitamin D levels above the sufficiency range of 30 ng/ml can reduce insomnia and improve sleep. Vitamin D works because the part of the brain that is responsible for sleep has a large concentration of vitamin D3 receptors, and when D is absent, sleep is disrupted.
Raise melatonin with tart cherry juice or a melatonin supplement.
Melatonin can directly influence your body’s core temperature as well as the sleep-wake cycle, making optimal levels at nighttime critical for sleep.
A natural (and delicious) way to raise melatonin is to drink tart cherry juice because it contains phytochemicals that reduce inflammation and lead the body to secrete more melatonin. For example, when 20 young volunteers drank tart cherry juice for 7 days they significantly improved sleep quality and duration.
Supplementing with melatonin will also work. Between 0.5 and 6 grams has been found to help people go to sleep, sleep longer, and improve sleep quality according to an analysis of 19 studies.