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Larger time zone changes, eastward travel, and evening arrivals are associated with poorer fatigue, sleep, and wellness in female national team footballers, but travel variables explain limited variance.

This observational study of 45 female national team footballers over 3 years (342 flights) found that larger time zone shifts, eastward travel, and evening arrivals were associated with increased fatigue, poorer sleep, and worse total wellness scores (P < .001 for time zone; P = .003 for fatigue direction; P = .001 for sleep direction; P = .026 for wellness direction). However, effect sizes were mostly small or trivial, and travel variables explained only 0.1% to 10% of variance in wellness ratings.

Last updated: Aug 4, 2026•0 RCTs•📖 Read as article →

Evidence Score

Evidence Score34/100
Human RCT☆☆☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★☆
Confidencelow

Study Evidence

Study 1. The Relationship of Travel Demands With Perceived Fatigue, Sleep, and Wellness of Female National Team Footballers.

observational

Graham SE, Clements E, Brown GA, Duffield R · International journal of sports physiology and performance (2026)

Participants: N/A
Duration: 3 years
Intervention: Travel variables (time zone difference, direction, arrival/departure times, trip type) were assessed as predictors.
Outcome: Perceived fatigue, sleep, stress, soreness, and overall wellness (self-reported up to 3 days posttravel).
Effect Size: Small or trivial effect sizes (exact values not reported; marginal R2 = .001-.10).
Population: 45 professional female national team footballers.

Result:

PubMed: 42532497DOI: 10.1123/ijspp.2025-0655

Mechanism Graph

Travel disrupts circadian rhythms due to time zone changes.
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Eastward travel causes greater circadian misalignment than westward.
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Evening arrivals may interfere with sleep onset and recovery.
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Result: Increased fatigue, poorer sleep, and worse wellness scores.

Limitations

  • ⚠Low explanatory power of travel variables (marginal R2 = .001-.10), suggesting other factors (e.g., training load, psychological stress) are important.
  • ⚠Observational design; no causal inference.
  • ⚠Self-reported outcomes may be subject to recall bias.
  • ⚠Sample limited to female national team footballers, limiting generalizability.

Frequently Asked Questions

Does eastward travel affect female footballers more than westward?▼

Yes, eastward travel was associated with higher fatigue (P = .003), poorer sleep (P = .001), and worse total wellness (P = .026) compared to westward travel.

How long does it take to recover after travel?▼

Most measures improved by 2 days postarrival (P < .001).

Are morning arrivals better than evening arrivals?▼

Morning arrivals were associated with better fatigue and sleep ratings than evening arrivals (P < .001).

Do travel variables fully explain post-travel wellness?▼

No, travel variables explained only a small portion of variance (marginal R2 = .001-.10), indicating other factors also influence wellness.

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References

  1. 1.Graham SE, Clements E, Brown GA, Duffield R. "The Relationship of Travel Demands With Perceived Fatigue, Sleep, and Wellness of Female National Team Footballers.." International journal of sports physiology and performance, 2026. PMID: 42532497 DOI: 10.1123/ijspp.2025-0655
Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.