The wide-reaching influence of sleep cannot be overstated. Yes, sleep is a vital time to restore your energy levels and let your immune system go full-force against any illness, but there are other roles of sleep that are less well-known, such as its role in regulating the male reproductive system.
For those struggling with male fertility, it may be time to take a look at your sleeping habits— the available scientific research suggests that this connection may be more influential than we suspect.
How Fertility is Affected by Circadian Rhythm
Conception is undeniably associated with key bedroom activities, but there may be an unsuspecting bedroom activity that is just as crucial to conception, and that’s sleep.
Specifically, your circadian rhythm is what regulates your sleep-wake cycles, and it may be closely tied to fertility.
In addition to cueing your body in to sleep and wake times, your circadian rhythm is responsible for modulating several physiological functions, such as your body temperature, hormone secretion, and heart rate—all of which are used to regulate this 24-hour cycle. However, if your suprachiasmatic nuclei—a small region of the brain in the hypothalamus—loses this rhythm, many functions can be affected, including the release of pulsatile sexual hormones like gonadotropin-releasing hormone (GnRH).
Two key hormones that GnRH releases are follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are involved in sperm and testosterone production, respectively. When there is an impairment in FSH and LH signaling, as seen in the case of disturbed circadian rhythm, men see poor sperm production and suboptimal testosterone levels.
Androgens, as well, are regulated by circadian rhythm, with them showing a 24-hour rhythm and peak in the mornings. Androgens are needed in men to develop and maintain secondary sexual characteristics, grow, prevent osteoporosis, maintain libido, and produce sperm. Yet, with our hormones relying on our circadian rhythm to manage their production timing, continued disruptions to the circadian rhythm may affect peak androgen levels.
Seeing how all these hormones are influenced by circadian rhythm, it’s clear that our circadian rhythm is a key player in ensuring our sexual hormones are produced when they should be and in the correct amount.
How Sleep Affects Fertility
We now know that our circadian rhythm can influence fertility by regulating hormone levels, but let’s take a closer look at the role sleep plays.
Sleep Affects Sperm Health
An incredibly important measure of fertility is how healthy the sperm are, and poor sleep may be dragging sperm health down.
In 2020, researchers enlisted nearly 1,000 men in a trial to see how sleep quality affects sperm count and sperm quality. They found that the men who had poor quality sleep had lower total motility and progressive motility, lower sperm counts, and poorer sperm morphology.
In essence, the trial showed that poor sleep led to poor swimmers, which can then lead to infertility struggles.
Yet another study on the effects of sleep on sperm health found that both sleeping too little or too long was associated with poorer sperm health, and this was partly because of an increase in anti-sperm antibody production (ASA) in the semen, which is a special antibody that attacks sperm.
Poor Sleep Increases Inflammation
Inflammation is the bane of most chronic conditions, and infertility can also feel its effects.
A study on 50 college students, who are notoriously sleep-deprived, examined how sleep influences the presence of inflammation by looking at sleep duration, sleep latency, sleep quality, and bedtime. They found a strong connection between inflammation, a short sleep duration, poor sleep quality, and a late bedtime.
As for how inflammation affects fertility, research has found that higher-than-normal levels of cytokines, which are immune substances that promote inflammation, are connected to impaired sperm function. Furthermore, many men who suffer from infertility also have acute or chronic inflammation in the genitourinary tract.
This research shows that inflammation can affect sperm function, and your sleep habits are a common contributor to inflammation.
Sleep Lowers Testosterone Levels
We briefly touched upon how our circadian rhythm influences testosterone levels, but let’s explore a study that digs into the effects of poor sleep.
A small study on college men found that testosterone levels were 10-15% lower after a 5-hour night of sleep versus nights when the same subjects were fully rested. With low testosterone levels associated with fertility, this study offers a connection for how sleep and infertility are connected.
Sleeping to Improve Fertility
If you have infertility, modifying your sleeping habits may help you give your sperm a boost.
The key is to build healthy sleep habits that allow you to get enough good, quality sleep each night and regulate your circadian rhythm, such as:
- Set a bedtime. It may seem childish, but setting a bedtime for yourself forces you to stick to it, and it can have numerous benefits. Not only can an early bedtime lower inflammation, but it can also aid in regulating your circadian rhythm, which can then help regulate your hormone levels. Even more, the better you are about sticking to your bedtime, the easier it’ll become to fall asleep.
- Follow a bedtime routine. With a bedtime in place, now create a routine that will help you prepare for sleep. Specifically, focus on stress-reducing activities, as stress not only keeps you up, but may also decline semen quality.
- Get moving. Exercising during the day not only helps to regulate your circadian rhythm and make falling asleep easier, but it may even help to improve your semen quality.
- Get some light. Your circadian rhythm uses light to regulate itself, and you can help by getting some sunlight first thing in the morning.
If your struggles with infertility persist, it may be time to see a doctor for greater assistance. However, improving your sleep is a great place to start, and getting more good-quality sleep is never a bad idea—more mobile swimmers is just one benefit.
