Eastward Jet Lag is Associated with Impaired Performance and Game Outcome in the National Basketball Association.
Level 3 - non-randomized controlled study
Retrospective longitudinal observational cohort study of match performance data (graded by design analogy)
PubMed 35784873 · doi:10.3389/fphys.2022.892681
What was done
Investigators analyzed 10 NBA regular seasons (2011/2012 to 2020/2021) comprising 11,481 games to evaluate the association between travel-related jet lag direction and performance. Multi-level mixed models evaluated fixed effects of jet lag direction (eastward vs. westward vs. no jet lag) alongside random factors (team, opponent, game time) and predicted circadian resynchronization rate. Home and away games were evaluated separately, and mediation analyses examined potential mechanisms.
What was found
Among home teams, eastward (but not westward) jet lag was associated with: - Reduced winning percentage: change (Δ) = -6.03% (p = 0.051, marginal) - Reduced points differential: Δ = -1.29 points (p = 0.015) - Reduced rebound differential: Δ = -1.29 rebounds (p < 0.0001) - Reduced effective field goal percentage differential: Δ = -1.2% (p < 0.01) Larger eastward jet lag magnitude further reduced home points differential (1 h Δ = -0.72 points, p = 0.07; 2 h Δ = -4.53 points, p < 0.05). No significant associations were observed for away team performance.
Why it matters
This study provides large-scale empirical evidence that circadian phase advances from eastward travel impair scoring, shooting efficiency, and rebounding in elite basketball teams returning home. It supports the use of chronobiology-informed travel schedules and circadian recovery strategies in professional sports leagues.
Limits
Findings rely on aggregate team box-score metrics and modeled circadian resynchronization rather than direct physiological measures of sleep duration, quality, or circadian phase markers. The association with home team winning percentage was marginally significant (p = 0.051), and findings from NBA travel schedules may not generalize to sports with different travel cadences.
Cited by
- supports The circadian literature indicates that it takes about an hour per day to adjust to time zone shifts, adjusting faster when traveling west than east.