Does lack of sleep lower testosterone in young men?
Conflicting. Of 4 studies that test it, 2 partly agree, 1 agrees and 1 disagrees.
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young men who cut their sleep short and want to know what it does to testosterone.
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The claim checked: Five nights of four or five hours' sleep gives young men the testosterone of a man about 10 years olderHear it at 1:13:34
What do the studies say?
Conflicting
One week of 5-hour nights lowered daytime testosterone by 10% to 15% in 10 young men. A trial of under 4 hours a night for 5 nights found no significant change, and another found only a trend. Men who already slept short had higher testosterone after 10-hour nights than after 6-hour nights.
Computed from 4 studies that test this point, each judged by two readers, in full.
Sources land on both sides.
10 more studies are waiting for a full read and do not count yet.
“let's say I take a group of really healthy young men and I limit them to four or five hours of sleep for five nights they will have a level of testosterone which is similar to someone who is probably 10 years older than them”
Matthew Walker, a guest on Huberman Lab · Dr. Matt Walker: The Biology of Sleep & Your Unique Sleep Needs | Huberman Lab Guest Series ·
1:13:34 on YouTube Comes up in 4 episodes of the show.
The study behind the claimThe retelling overstates it
What did the study actually test?
On tape: four or five hours for five nights. The study gave 5-hour bedtimes for 8 nights and sampled after the seventh night. The 10 years older comparison comes from the authors setting a 10% to 15% drop against 1% to 2% a year with aging; no older men were measured.
Effect of 1 week of sleep restriction on testosterone levels in young healthy men.JAMA, 2011. Within-person laboratory study: 3 nights of 10-hour bedtimes, then 8 nights of 5-hour bedtimes, blood sampled every 15 to 30 minutes for 24 hours, 10 healthy men, mean age 24.3.
What was saidWhat the study did
What was given
DiffersFour or five hours of sleep for five nights5-hour bedtimes for 8 nights (4 h 48 min of sleep), sampled after the seventh night
Compared with
DiffersA man about 10 years olderThe same men after 3 nights of 10-hour bedtimes
What was measured
MatchesTestosterone levelTotal testosterone across the day (8 AM to 10 PM)
Who took part
MatchesReally healthy young men10 healthy men, mean age 24.3
What it found
“During waking hours common to both conditions (8 AM-10 PM), testosterone levels were lower after sleep restriction than in the rested condition (16.5 [2.8] nmol/L vs 18.4 [3.8] nmol/L; P = .049).”
“Daytime testosterone levels were decreased by 10% to 15% in this small convenience sample of young healthy men who underwent 1 week of sleep restriction to 5 hours per night, a condition experienced by at least 15% of the US working population.”
This work was supported by the National Heart, Lung, and Blood Institute grant 5R01HL72694-5, by the National Institute of Diabetes and Digestive and Kidney Diseases grant P60DK-020595, and by the National Institutes of Health grant MO1-RR-00055. Two readers agreed on the label, and the paper was read in full.
The point checkedConflicting
In healthy young men, sleeping only four or five hours a night for about five nights to a week lowers testosterone
Agree 1
other primary study · 2011 · cited on tape
“Daytime testosterone levels were decreased by 10% to 15% in this small convenience sample of young healthy men who underwent 1 week of sleep restriction to 5 hours per night, a condition experienced by at least 15% of the US working population.”
Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA Who: 10 healthy young men, mean (SD) age 24.3 (4.3) years, mean BMI 23.5, University of Chicago volunteers
PMID 21632481
Partly agree 2
trial or observed group · 2012
“While testosterone did not change significantly with sleep restriction, a trend was observed, with levels reduced on SR5 compared to B1.”
Impact of five nights of sleep restriction on glucose metabolism, leptin and testosterone in young adult men. PLoS One Who: 14 healthy men aged 22-36 y (27.4±3.8) completing the protocol, from 16 recruited, habitual sleepers of 7.0-8.5 h, BMI 19-30
PMID 22844441
controlled trial · 2015
“Fasting morning testosterone levels were significantly higher following 10 h compared to 6 h (2·2 n m (0·2, 4·2); P = 0·03) in both the group as a whole ( n = 8) and in the younger group alone ( n = 5) (Fig. 5 e).”
Metabolic and hormonal effects of 'catch-up' sleep in men with chronic, repetitive, lifestyle-driven sleep restriction. Clin Endocrinol (Oxf) Who: 19 healthy men aged 19-49 (mean 28.6) with chronic lifestyle-driven weekday sleep restriction (midweek sleep 6 h 12 min) and weekend catch-up sleep; 18 aged <=35, 3 aged >35
PMID 25683266
Disagree 1
controlled trial · 2019
“In the present study, neither severe and acute (<4 h/night for 5 nights) nor mild and chronic (1.5 h/night for 6 wk) SR significantly affected plasma testosterone levels in healthy young men.”
Sleep restriction and testosterone concentrations in young healthy males: randomized controlled studies of acute and chronic short sleep. Sleep Health Who: Study 1: healthy men aged 30-45 y (mean 36.6), BMI 22-26, inpatient crossover; Study 2: men aged 20-40 y (mean 30.1), BMI 25-29.9 or 23-24.9 with a parent with obesity, outpatient crossover
PMID 31416797
What else was said but not tested?
The drop matches the testosterone of a man about 10 years older