HERSHEY, Pa., Oct. 12 (UPI) -- Making up for lost sleep during the workweek over the weekend helps repair some damage to the body, but not all, U.S. researchers say.
Study leader Alexandros N. Vgontzas of the Pennsylvania State University College of Medicine and colleagues placed 30 volunteers on a sleep schedule that mimicked a sleep-restricted workweek followed by a weekend with extra recovery sleep.
At various points along this schedule, the researchers assessed the volunteers' health and performance using a variety of different tests.
Previous research showed even a few days of lost sleep can have adverse effects, including increased daytime sleepiness, worsened daytime performance, an increase in molecules that are a sign of inflammation in the body and impaired blood sugar regulation, Vgontzas said.
The researchers found the volunteers' sleepiness increased significantly after sleep restriction, but returned to baseline after recovery sleep. Levels of a molecule in blood that's a marker for the amount of inflammation present in the body increased significantly during sleep restriction, but returned to normal after recovery.
Levels of a hormone that's a marker of stress didn't change during sleep restriction, but were significantly lower after recovery.
However, the volunteers' measures on a performance test that assessed their ability to pay attention deteriorated significantly after sleep restriction and did not improve after recovery.
This last finding suggested recovery sleep over just a single weekend might not reverse all the effects of sleep lost during the workweek.
The findings were published in the American Journal of Physiology-Endocrinology and Metabolism.