Shift Work Adaptation

Night work forces behaviour against an endogenous circadian pacemaker that is anchored primarily by light. Complete adaptation is rare in rotating schedules, and shift work disorder — excessive sleepiness and insomnia tied to the schedule — affects a substantial minority of workers. Long-term night work is associated with elevated cardiometabolic risk and is classified by IARC as a probable carcinogen. The practical goal is damage limitation through light control, sleep protection and strategic napping rather than complete phase reversal. Drowsy driving after night shifts is the most immediate hazard.

1) Get bright light during the first half of the night shift and avoid it in the last hours before sleep. 2) Wear dark wraparound sunglasses on the commute home — this is the highest-yield single habit for protecting daytime sleep. 3) Make the bedroom completely dark, cool and quiet, and defend it as non-negotiable. 4) Take melatonin 0.5-3mg before daytime sleep; timing matters far more than dose. 5) Nap strategically — a 20-30 minute nap before the shift, plus a mid-shift nap where permitted. 6) Use caffeine early in the shift and stop at least six hours before intended sleep. 7) Eat main meals before the shift and keep night eating light; night-time eating worsens glucose handling. 8) Prefer forward-rotating schedules and avoid driving when severely sleepy.

• •Bright light early in shift
• •Dark sunglasses on morning commute
• •Blacked-out bedroom
• •Strategic napping
• •Caffeine timing
• •Meal timing before shifts
• •Forward-rotating rosters