Circadian athletic variations when traveling in the Canadian Football League

Previous studies have shown a circadian disadvantage in evening games in professional sports teams traveling westward. This effect has been in part attributed to the circadian misalignment between the traveling team and the local team. Compared to the National Football League (NFL) teams, Canadian Football League (CFL) teams often travel longer distances and play at later times. As such, the objective of the present study was to investigate the circadian disadvantage in the CFL. Data from 8 years of CFL regular season games were extracted from online databases (2014-2021). Wins, score differentials, first downs, average total, passing, penalty, kickoff yards, pass completion percentages, interceptions, fumbles, sacks, and time of possession were extracted for both the offense (made) and defense (allowed) for every away evening game (after 18:00 h; n = 387), with the direction of travel (eastward, same time-zone, westward). One-way ANOVAs Direction of Travel (eastward, same time-zone, westward) on each performance variable were computed to study the circadian effect. Linear regression analyses were done to investigate the effect of the distance traveled by the away team (longitude traveled) on each variable. Significant effects of the direction of travel were found for team variables: score differentials and time of possession. Significant results were also found for both offensive variables: first downs, average kickoff return yards, fumbles; and defensive variables: first downs allowed, average yards per play, average passing yards allowed, average kickoff yards allowed. Post hoc t-tests revealed a circadian disadvantage to teams traveling westward and a circadian advantage for teams traveling eastward. Regression analyses confirmed that performance worsens as distance increases when traveling from east to west and improved when traveling from west to east. These results are consistent with previous findings showing that evening games in some professional sports present important challenges for teams traveling westward. However, there is also an advantage for teams traveling east, suggesting that for CFL players, travel fatigue may have less of an impact than the circadian alignment advantage of traveling eastward. In addition, our results highlight that circadian advantages and disadvantages should be considered not only in relation to teams, but also at an individual level with regard to each player's performance.