October 9, 2013
Science Daily/American Physiological Society (APS)
A new study assesses the effects of extended “weekend” recovery sleep following “one workweek” of mild sleep restriction on sleepiness/alertness, inflammation and stress hormones.

Not surprisingly, the researchers found that after 5 days of restricted sleep, the subjects were significantly sleepier on both objective and subjective tests compared to baseline levels. Their interleukin-6 levels increased sharply during restricted sleep, though their cortisol levels remained the same. Their performance on the attention test deteriorated. After 2 days of recovery sleep, both objective and subjective tests showed that the volunteers were less sleepy. Their interleukin-6 levels reduced, and their cortisol levels decreased significantly compared to baseline, possibly suggesting that the volunteers were sleep deprived before the study started. Notably, their performance on the attention test didn't improve after recovery sleep.

Though many indicators of health and well being improved after recovery sleep, these findings suggest that extra sleep may not fix all the deficits caused by lost sleep during the workweek.

"Two nights of extended recovery sleep may not be sufficient to overcome behavioral alertness deficits resulting from mild sleep restriction," the authors write. "This may have important implications for people with safety-critical professions, such as health-care workers, as well as transportation system employees (drivers, pilots, etc.)."
http://www.sciencedaily.com/releases/2013/10/131009125740.htm