AI quick summary
- Jet lag affects performance more than fitness — expect roughly one day per time zone crossed
- Light exposure and meal timing shift your circadian clock faster than melatonin alone
- Hydration, mobility, and compression reduce long-haul flight risks
- Plan the first 72 hours on the ground around easy riding and morning sunlight
/ 01
What jet lag actually does
Crossing time zones desynchronises your circadian rhythm from local time, and cycling performance goes with it. Peak power output, perceived exertion, reaction time, and mood all degrade — by 5-10% in the first days. The rule of thumb is one day per time zone crossed to fully adjust.
Eastward travel is harder than westward because advancing your clock (going to bed earlier than your body wants) is harder than delaying it. Aging also slows adjustment, and masters cyclists crossing more than five zones should plan for an extra day or two.
/ 02
Practical time-zone strategy
Managing travel across zones — west versus east, light and timing
| Strategy | Westward travel | Eastward travel |
|---|---|---|
| Begin shifting sleep | 3-4 days before, delay by 1h per day | 3-4 days before, advance by 1h per day |
| Light exposure | Bright light in the evening | Bright light in the morning |
| Caffeine cutoff | Later in the day | Earlier — before 14:00 local |
| Melatonin | Skip, or 0.5 mg on waking | 0.5-3 mg 30 min before target bedtime |
| First ride timing | Late afternoon local | Morning local, easy |
/ 03
The flight itself
Long flights dehydrate you — cabin humidity runs 10-20%, and cyclists who arrive in hot climates compound the deficit. Drink 250 ml of water per hour in flight, avoid alcohol (it worsens dehydration and disrupts sleep), and stand or walk every 90 minutes.
Compression socks reduce ankle swelling and lower the small but real risk of deep vein thrombosis. A few calf raises in your seat are not silly — they keep venous return going. Pack ride-day food; airport food is typically carbohydrate-light and sodium-poor.
/ 04
Hydration, climate, and the first 72 hours
After a long flight plus a climate jump — say, cool temperate to tropical — expect heart rate to run 10-15 bpm higher for any given power for the first 3-5 days. Add electrolytes to your bottles, ride by feel rather than by power in the first sessions, and accept that intervals at goal pace may simply not be there yet.
Sunlight is the strongest circadian re-setter. Get outside for 20-30 minutes in the morning of local days one through three, even if it is cloudy. Meals on local time, not home time, anchor your rhythm.
/ 05
When to seek medical advice
Calf pain, swelling, or shortness of breath after a long flight can indicate deep vein thrombosis or pulmonary embolism — these are medical emergencies. Persistent fatigue, recurrent infections, or unexplained performance drops lasting more than two weeks after travel warrant a check-in.
For general travel wellness, this guide is informational and does not replace individualised medical advice, especially for riders with cardiovascular risk factors.
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