Retaining home-base sleep hours to prevent jet lag in connection with a westward flight across nine time zones.
The aim of this study was to test a possible countermeasure to jet lag: letting air crew retain their home-base sleep/wake pattern during layover. Instead of their usual adoption of local sleep hours, 19 flight attendants were scheduled to a westward layover (50 h) flight (Copenhagen-Los Angeles, -9 h) on two occasions. On one trip, crews adopted the local sleep pattern, and on the other trip, the crew retained home-base sleep hours. Subjects were monitored for 10 days before, during, and after the flight; they wore activity loggers and gave ratings through sleep/wake diaries and a questionnaire. Ratings of jet lag symptoms and sleepiness were greatly reduced during layover, but not at home, for the home-base condition. It was also found that jet lag feelings seemed to be related mainly to mean sleepiness ratings (multiple regression; 16%, beta = 0.46) and to the number of awakenings (6%, beta = 0.29) during sleep. It is concluded that retaining the home-base sleep pattern may reduce jet lag during layover.
IPM/Karolinska Institute, Stockholm, Sweden.
A
A
Lowden
T
T
Akerstedt
D000328:Adult; D000337:Aerospace Medicine; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires; D013548:Sweden; D014195:Travel; D014940:Work Schedule Tolerance / Q000502:physiology