The Importance of Sleep for Optimal Testosterone Production

“Sleep is a symptom of caffeine deprivation.” —Author Unknown


Sleep is commonly viewed as a restorative process that influences the nervous, neuroendocrine and immune systems. Sleep is considered critical for the maintenance of health; abnormal sleep patterns are associated with increased risk of cardiovascular disease, mood disorders, chronic pain and a shortened lifespan.11 In a lot of ways, sleep is like sex— you can never get too much of it. In addition, sleep is a lot like your boss when he’s working...don’t disturb him or he gets pissed. Well, your body is the same way— don’t disturb its sleep or he will take it out on you.

The Consequences of No Sleep
All bodybuilders know that getting eight to 10 hours of sleep a night is important for training recuperation, but this guideline is often neglected. Who the hell has time for eight to 10 hours of sleep anymore? People have chaotic work deadlines, kids, a social life and hitting it hard in the gym. Sleep is the one thing bodybuilders (or anyone else for that matter) will sacrifice to get a few more things done. As stated earlier, not getting the right amount of sleep will cause harmful effects on glucose tolerance, GH secretion and lower immune parameters, as well as increasing cortisol and adrenaline.1,2

A 1999 study in The Lancet reported that when healthy young men had four hours of sleep for six nights, it resulted in a harmful impact on carbohydrate metabolism and endocrine function. Subjects experienced an increase in insulin resistance and reduced thyroid levels. In addition, evening cortisol and increased sympathetic activity of the nervous system was also reported.18 Other studies have documented that sleep deprivation doesn’t give the nervous system a chance to rest and results in elevated adrenaline levels. One study demonstrated that subjects exposed to sleep deprivation (i.e., 3.3 hours of sleep) resulted in a significant elevation in circulating levels of norepinephrine and epinephrine during the night.15 Circulating catecholamines are normally supposed to decline with sleep.

 Another less well-known hormone identified as increasing during sleep is prolactin. Now don’t freak out, you’re not going to start squirting milk out of your nipples like a breastfeeding mother, but circulating levels of prolactin rise during the night with sleep. There’s a linkage between GH and prolactin secretion during non-REM sleep in humans. Prolactin and GH share 40 percent of the same protein sequence. Prolactin is secreted in the anterior portion of the brain, but is also synthesized and secreted by a broad range of other cells in the body, including various immune cells. It’s interesting that sleep deprivation reduces nightly prolactin levels, which may explain why there’s reduced immune functionality with sleep loss. Mice that are made genetically deficient in prolactin are immunocompromised to which sleep loss shares a resemblance.12 Prolactin has also been shown to be a regulator of testosterone. When men were given the anti-depressant drug, haloperidol (which lowers dopamine, but results in an increased release of the prolactin), the resulting significant increase in prolactin corresponded with a significant increase in testosterone 60 minutes later. In the same study, the control group’s mean testosterone levels showed the normal decline during daytime hours. This delay between increased prolactin and increased testosterone is consistent with a similar delay between the increases of these two hormones occurring at night during sleep.13