Less Sleep, Less Testosterone!
Targeted Readership: Men
Theme: Chemistry
Length: 650 words
Reading Time: 3.5 minutes
Sleep and Testosterone
Sleep quality and quantity affect testosterone levels.
“Plasma testosterone levels display circadian variation, peaking during sleep, and reaching a nadir in the late afternoon, with a superimposed ultradian rhythm with pulses every 90 min reflecting the underlying rhythm of pulsatile luteinizing hormone (LH) secretion. The increase in testosterone is sleep, rather than circadian rhythm, dependent and requires at least 3 hours of sleep with a normal architecture. Various disorders of sleep including abnormalities of sleep quality, duration, circadian rhythm disruption, and sleep-disordered breathing may result in a reduction in testosterone levels.”
Wittert, 2014*
The paper also says that the male body reaches its highest testosterone levels during sleep. This might explain the morning wood phenomenon.
Good Sleep Promotes Good Health
A reader shared this book with me on 2023/8/29.
Why We Sleep, Matthew Walker, Simon and Schuster, 372 pages [PDF]
Concerning our study of male body chemistry, Chapter 8 covers Sleep Deprivation and the Body, including sections on,
- Sleep Loss and the Cardiovascular System (p.161)
- Sleep Loss and Metabolism: Diabetes and Weight Gain (p.166)
- Weight Gain and Obesity (p.168)
- Sleep Loss and the Reproductive System (p.175)
- Sleep Loss and the Immune System (p.178)
- Sleep Loss, Genes, and DNA (p.183)
Also, Chapter 9 (p.188) is an interesting overview of REM-Sleep and Dreaming.
Concerning the effects of sleep on male reproductive health, on pages 175-176, Walker’s book says,
“If you have hopes of reproductive success, fitness, or prowess, you would do well to get a full night’s sleep every night. Charles Darwin would, I’m sure, cleave easily to this advice, had he reviewed the evidence I now present.
Take a group of lean, healthy young males in their mid-twenties and limit them to five hours of sleep for one week, as a research group did at the University of Chicago. Sample the hormone levels circulating in the blood of these tired participants and you will find a marked drop in testosterone relative to their own baseline levels of testosterone when fully rested. The size of the hormonal blunting effect is so large that it effectively “ages” a man by ten to fifteen years in terms of testosterone virility. The experimental results support the finding that men suffering from sleep disorders, especially sleep apnea associated with snoring, have significantly lower levels of testosterone than those of similar age and backgrounds but who do not suffer from a sleep condition.
Uttering the results of such studies will often quell any vocal (alpha) males that I occasionally come across when giving public lectures. As you may imagine, their ardent, anti-sleep stance becomes a little wobbly upon receiving such information. With a genuine lack of malice, I proceed to inform them that men who report sleeping too little—or having poor-quality sleep—have a 29 percent lower sperm count than those obtaining a full and restful night of sleep, and the sperm themselves have more deformities. I usually conclude my response with a parenthetical low blow, noting that these under-slept men also have significantly smaller testicles than well-rested counterparts.
Rare podium fracases aside, low testosterone is a clinically concerning and life-impacting matter. Males with low testosterone often feel tired and fatigued throughout the day. They find it difficult to concentrate on work tasks, as testosterone has a sharpening effect on the brain’s ability to focus. And of course, they have a dulled libido, making an active, fulfilling, and healthy sex life more challenging. Indeed, the self-reported mood and vigor of the young men described in the above study progressively decreased in lockstep with their increasing state of sleep deprivation and their declining levels of testosterone. Add to this the fact that testosterone maintains bone density, and plays a causal role in building muscle mass and therefore strength, and you can begin to get a sense of why a full night of sleep—and the natural hormonal replacement therapy it provides—is so essential to this aspect of health and an active life for men of all ages.”
Why We Sleep, by Matthew Walker
If you like what you’ve read in this excerpt, click on the PDF link and read more of Walker’s book.
* H/T: Oscar
References
- Wittert, G. The relationship between sleep disorders and testosterone in men. Asian J. Androl. 2014 16(2):262-5. DOI: 10.4103/1008-682X.122586. PMID: 24435056; PMCID: PMC3955336.
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