The word testosterone is one you have surely heard from time to time. But there’s a lot more to it than you may realize. In fact, testosterone plays a very large role in many different systems throughout the body.
From the reproductive system and sexuality, to bone density and muscle mass, testosterone has a hand in it all.
But what you may not know is that sleep plays a large role in testosterone levels and production. It may sound counter intuitive, but it’s true. The time you spend snoozing can have a huge effect on this important hormone.
Before we get into that, let’s get a little background on testosterone and how it works.
Testosterone is an important hormone that plays a variety of roles throughout a man’s life. We often associate this hormone with puberty and the development of the reproductive organs. However, it is playing its part long before puberty sets in.
A male begins to produce testosterone as early as seven weeks after conception. At this stage, the testosterone is working to form the male genitalia that we recognize when the baby is born.
Once puberty set in, testosterone becomes responsible for the many changes adolescent males experience. A deeper voice, a beard, and the maturation of the sexual organs can all be attributed to testosterone.
The levels of the hormone found in the body usually peak during the late teen years and remain steady until around the age 30. At this point, it is normal to see about a 1% decrease each year for the remainder of a man’s life.
Testosterone is synthesized in the body from cholesterol. This may lead you to think that high cholesterol means you have more testosterone, but this is not the case. The amount of testosterone in the body is regulated by the pituitary gland in your brain.
This message then gets relayed to the testicles where most of the testosterone is actually produced. The adrenal glands, which are located right above your kidneys also help with production.
Now that we know where testosterone is produced, let’s look at when it is produced. This is where your sleep schedule becomes so important. Scientists have found that testosterone levels increase as you sleep and decrease the longer that you are awake. More specifically, the highest levels of testosterone production happen during REM sleep.
REM sleep is the portion of your sleep cycle that helps to replenish the mind and body, so it makes sense that this is when we would see higher levels of hormone production. Typically, a person will get three to five REM cycles per night, with the longest occurring about an hour before we wake up.
What is a little surprising is how quickly neglecting your nightly 8 hours can derail testosterone levels. One study found that getting 5.5 hours of sleep or less for just one week can cause up to a 15% decrease in testosterone levels. Those 5.5 hours were simply not enough for the body to get the REM sleep necessary to receive those benefits.
This isn’t something that only happens as you get older either. A study performed at the University of Chicago tested a group of men with an average age of 24. The men slept 10 hours the first three nights and were then limited to 5 hours for the following 8 nights. The team tracked a marked decrease in testosterone levels even in young healthy men.
As most of us know, the primary role of testosterone is as a sex hormone. Not only does it dictate reproductive organ development, it is also responsible for the fertility and libido of a male.
As we mentioned at the beginning of this article, testosterone plays a hand in many other important body processes. Let’s take a look at some of the other things it does:
Hair Growth – When the amount of testosterone that the body produces spikes during puberty, it jump starts the growth of hair. This not only includes facial hair and hair under the arms, but also on the chest, legs and arms.
As testosterone levels drop with age, it is not uncommon to see a loss of that body hair over time.
Heavier Bones – Testosterone increases bone density which is very important to the health of each individual. As testosterone levels decrease with age, males are more likely to develop osteoporosis which can lead to an increase in bone fractures and potential breaks.
Muscle Growth – Testosterone plays a key role in the development of muscle growth and strength. Higher levels of the hormone mean an increase in neurotransmitters. These encourage tissue growth which makes it easier for a male to build muscle when they exercise.
Metabolism – Testosterone plays a role in fat metabolism, actually helping men to burn fat more efficiently and effectively.
Red Blood Cell Production – As the hormone makes its way around, it tells your bone marrow to produce more red blood cells. Red blood cells carry oxygen to your cells, helping them to their job the way they should.
Heart Health – Doctors and scientists are currently testing to see the effects of testosterone and heart health. A study published in The Aging Male Journal shows that there is a link between low testosterone levels and cardiovascular disease.
While there is not definitive proof yet, studies are working to show that testosterone therapy in older men may help them to avoid heart attacks.
How to Know If You Should Get Tested
Testosterone levels can be tested by your doctor with a simple blood test and there are treatments to help regulate it as you get older. But how do you know if you should reach out to your healthcare provider?
Here are a few tell-tale signs that you can be aware of:
– Low libido
– Erectile dysfunction that does not respond to medication
– Low energy
While there are testosterone replacement therapies available, remember that your lifestyle, specifically sleep, plays a large role.
Making sure to get your recommended 8 hours of sleep is beneficial for your body, mind and testosterone levels.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3955336/ The relationship between sleep disorders and testosterone in men Gary Wittert; 2014
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445839/ Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men: Rachael Leproult, PhD and Eve Van Cauter, PhD; 2011
https://www.tandfonline.com/doi/full/10.1080/13685538.2018.1479387 Analysis of cardiovascular risk factors associated with serum testosterone levels according to the US 2011–2012 National Health and Nutrition Examination Survey. Chunhua Deng, Zhichao Zhang, Hongun Li, Peng Bai, Xian Cao, Adrian Sandra Dobs; 2018
https://www.jsm.jsexmed.org/article/S1743-6095(18)30944-5/fulltext Testosterone and Cardiovascular Risk: Meta-Analysis of Interventional Studies. Giovanni Corona, MD, PhD1, Giulia Rastrelli, MD, PhD2, Giuseppe Di Pasquale, MD3, Alessandra Sforza, MD1, Edoardo Mannucci, MD, PhD2,4, Mario Maggi, MD, PhD2; 2018