Effects of long-haul transmeridian travel on physiological, sleep, perceptual and mood markers in Olympic team support staff.
Level 4 - case-series / case-control
Prospective uncontrolled before-and-after observational case series
PubMed 36367300 · doi:10.1080/07420528.2022.2139186
What was done
Nine Irish Olympic team support staff members (2 males, 7 females; mean age 34.3 ± 8.3 years) were assessed before and after an eastward long-haul flight across eight time zones (approximately 24 hours total travel time) to Japan for the Tokyo 2020 Summer Olympic Games. Perceived jet lag, travel fatigue, mood states, and morning and evening salivary cortisol were measured during the pre-travel week (baseline), on post-travel days 1 to 8 (C1–C8), and on day 15 (C15). Sleep duration and quality were evaluated using actigraphy and self-reported sleep diaries.
What was found
Participants reported significant jet lag for 6 days post-travel (p < .05). Morning salivary cortisol decreased by 66% on C1 and remained significantly lower than baseline through C6 (p ≤ .03). Perceived sleep quality worsened on C1, C2, C4, and C5 (p ≤ .04). Actigraphy demonstrated significantly shorter sleep duration on C2, C3, and C6 (p ≤ .01) and lower sleep efficiency on C2 and C6 (p ≤ .04), with sleep measures normalizing by C7. Evening mood assessments showed significant increases in confusion (C2, C3; p ≤ .02), fatigue (C2, C3; p ≤ .03), and depression (C3, C7; p < .05), alongside reduced vigor (C2, C6, C7; p < .05) that remained low through C15.
Why it matters
This study provides objective and subjective recovery timelines for non-athlete Olympic support staff, showing that circadian markers and sleep take seven days to recover following long-haul eastward travel across eight time zones.
Limits
The study had a very small sample size (n = 9) with a female skew (7 of 9). There was no unexposed control group, and external stressors associated with pre-Olympic preparations and COVID-19 pandemic restrictions could have confounded mood and cortisol measures.
Cited by
- contradicts Following an international flight, it takes the human body approximately 15 days to fully recover its physiological architecture and restore blood glucose regulation.