-Night workers go against the available cues from zeitgebers as they sleep during the day and have to be alert at night.
-Bightworkers experience a circadian trough of decreased alertness... ocurring between midnight when cortisol levels are lowest and 4:00am when core body temperature is at its lowest.
-Workers who day sleep experience sleep problems because when they finish it is bright so there are other interruptions and daylight reduces sleep quality. Poor daytime sleep makes it more difficult for shift workers to stay awake through the night, espesh when the circadian trough is hit.
-There is a link between shift work andorgan disease... those working shift for more than 15 years were 3x more likely to develop heart diesase than non-shift workers.
-Jet lag is used to refer to the physiological effects of disrupted circadian rhythms. Biological rhythms are not equipped to cope with sudden and large changes. Side effects linked with jet lag.
-Performance decrement studies can help demonstrate the debilitating effects of jet lag... studying American major league baseball teams.