Researchers at the University of Chicago have stated that sleeping just 5
hours per night might lower the testosterone levels. Men release most of their
testosterone during sleep and so scientists wanted to see if less sleep meant
less of the hormone.
10 healthy and lean young men with an average age of 24 were part of the
study. These men spent 3 nights in a lab sleeping up to 10-hours, followed by 8
nights sleeping less than 5-hours. Blood samples showed that testosterone
levels were 10-15% lower when men slept 5-hours compared with when then slept for
10-hours. These men also reported a decline in their mood, energy and sense of
well being during the 5-hour phase.
According to Professor Eve Van Cauter, 15% is not an insignificant amount as
it is about the amount that occurs with normal aging by 10-15 years. This means
a week of bad sleep is like aging a decade or more. This study has been
published this week in the Journal of the American Medical Association and is funded
by the National Institutes of Health.