Less sleep robs young men of testosterone
Healthy young men who skimp on sleep have lower testosterone levels, finds a new study. For men, sleep loss can zap reproductive health, well-being and muscle mass, compared to getting a full 7 to 8 hours of rest every night.
Less testosterone from lack of sleep means less vigor
According to the research, published in the Journal of the American Medical Association (JAMA), lower testosterone also means fewer muscles, lower bone density, and less vigor.
Eve Van Cauter, PhD, professor in medicine and director of the study, compared testosterone levels among healthy, lean young men when they slept up to ten hours and less than five, finding sleep loss disrupts the endocrine system, causing a 10 to 15 percent dip in testosterone levels.
An important note for men is that testosterone levels reached their lowest levels between 2pm and 10pm on days when sleep was restricted for the study.
The investigation was conducted on ten men recruited from the University of Chicago campus area. The men in the study were 24 years old on average.
The participants also underwent a series of psychological and physical tests to screen for endocrine or psychiatric disorders.
For three nights the young men slept up to ten hours. Following the three nights of short sleep, the participants slept less than five hours for three weeks.
Researchers obtained blood samples every 15 to 30 minutes for 24 hours on the last day of each experiment.
One week of poor sleep leads to lower testosterone
After just one week of short sleep duration, testosterone loss was noted from the blood samples. The men also reported feeling moody and experienced less vigor, correlating with dips in hormone levels.
Low testosterone can affect concentration, mood, libido and energy levels. Levels of the hormone normally decline one to two percent a year with aging.
The new study shows young men who sleep less than five hours a night, when testosterone is released, face negative health consequences that are directly related to lower levels of the hormone.
"As research progresses, low sleep duration and poor sleep quality are increasingly recognized as endocrine disruptors," Van Cauter said
Young men who sleep less have the testosterone levels of a male ten to fifteen years older. The finding is important, considering half of the working U.S.population sleeps less than five hours a night.
Sleeping less than five hours a night can rob young men of testosterone needed for vigor, muscle and bone mass and reproductive health. The study found one week of restricted sleep lowered testosterone levels 10 to fifteen percent in the young men studied.
JAMA. 2011;305(21):2173-2174. doi:10.1001/jama.2011.710
“Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men”
Rachel Leproult, PhD; Eve Van Cauter, PhD
Updated January 26, 2014