Understanding Jet Lag

East vs West

Travelling east is harder than west. Moving west extends your day — your body naturally adapts to longer days more easily. Moving east shortens your day, which fights against your circadian rhythm. A cross-Atlantic UK → New York flight (west, 5 zones) is significantly easier than UK → Tokyo (east, 9 zones).

Recovery Timeline

A general rule: 1 day of recovery per time zone crossed when travelling east, 0.5 days when travelling west. Crossing 8 time zones east = approximately 8 days for full resynchronisation. For short trips, staying on home time is sometimes better than adapting.

Accelerating Recovery

Light exposure is the most powerful circadian reset tool. Get bright light in the morning at your destination (for eastward travel) and avoid bright light in the evening. Melatonin 0.5–1mg taken at local bedtime for 3–4 nights significantly shortens adaptation. Stay hydrated and avoid alcohol.

Jet Lag Calculator

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