Phase shifts of the human circadian system and performance deficit during the periods of transition: I. East-west flight.

Although previous East-West and West-East flight effected a primary shift of circadian periodicity, as manifested by physiological functions, the North-South flight did not and there was, however, a significant increase of subjective fatigue, as in the other flights.

Abstract

Abstract : At periodic intervals throughout the biological day, biomedical assessments were made for a week prior to jet flight to Santiago, Chile, for 12 days at Santiago, and for a week following return to Washington, D.C. Although previous East-West and West-East flight effected a primary shift of circadian periodicity, as manifested by physiological functions, the North-South flight did not. There was, however, a significant increase of subjective fatigue, as in the other flights. The significant impairment of psychological performance produced by the East-West but not the West-East flight was not shown by the North-South flight. (Author)