What are the effects of severe sleep deprivation and insufficient sleep on middle-age men? A study in the July issue of the journal SLEEP looked at 18 healthy French men ages 46 to 55. Sleep deprivation and restriction
immediately affected their performance and vigilance, but they adapted after three days. And it only took one good night’s sleep for them to recover.
To study the consequences of sleep deprivation and restriction, the men slept normally for the first night. But on the next night they either had no sleep or slept only four hours during the next five nights. The ability to perform a task and continue to perform that task were measured.
Sleepiness was determined in the men immediately following the four hours of sleep. The amount of time it took to fall asleep was as short for men deprived of a night’s sleep as it was for the men sleeping only four hours. Falling asleep in a short time is considered a sign of a sleep disorder. Reaction times decreased after the second day of a four-hour sleep and reached the same levels as men completely deprived of sleep. But the four-hour sleep times also appeared to have little effect after three nights. In the end, alertness and performance for all men was restored after an eight-hour recovery night of sleep.