Study published in Science Tanslational Medicine, January 13, 2010, Vol. 2, Issue 14, p. 14ra3. DOI: 10.1126/scitranslmed.3000458. The authors examined sleep loss and the effects of attempts to catch up on sleep. "Despite recurrent acute and substantial chronic sleep loss, 10-hour sleep opportunities consistently restored vigilance task performance during the first several hours of wakefulness. However, chronic sleep loss markedly increased the rate of deterioration in performance across wakefulness, particularly during the circadian night."

The study shows that more than one long sleep period is needed to restore the body after a long period of sleep loos.