Internal clocks affect shift worker health, study finds

Biological predispositions toward morning or evening alertness determine how well a health care professional can adapt to night shift schedules, according to the study, which is yet to be published. Morning-type employees working night shifts experienced the highest rates of drowsy driving and mental health diagnoses, while night owls working day shifts had higher rates of obesity and elevated blood sugar. Fatigue, caused by working long shifts or consecutive nights, can impair attention, reaction time and decision-making. The study found chronic fatigue ─ representing a cumulative physiological burden ─ was the strongest predictor of burnout, comprising more than 50% of the variability in burnout scores and was a bigger factor than staffing levels or workload alone. Organizational policies should recognize fatigue as a biological risk, rather than a performance issue, the author says. (Rutgers news release, 3/25/26)