Anecdotal reports regarding the 2013 FINA World Swimming Championships held in Barcelona suggested that swim performances were biased, presumably due to a current.
Purpose: The purpose of this study was to analyze the swimmers' performance data in order to determine the merit of these rumors.
Methods: The mean time difference between odd and even 50-meter lengths for each lane in the 1500-meter Freestyle was compared. For each 50-meter event, a percent change in performance from the preliminaries to semifinals and semifinals to finals was calculated for all qualifying swimmers. Observations were grouped according to the swimmers' lane assignments.
Results: For the 1500-meter Freestyle, lane assignment significantly affected the time difference between odd and even 50-meter lengths (P < 0.001). The change in performance for the 50-meter events was also affected by lane assignment (P < 0.001). When swimmers transitioned from Lanes 1-4 for their first swim (preliminaries or semifinals) to Lanes 5-8 for their second (semifinals or finals), their performance time improved 1.11% (95% CI, 0.82 to 1.41%), which was significantly greater than any other lane change scenario. When swimmers were in Lanes 5-8 for their first swim and Lanes 1-4 for their second, their performance time was slower by 0.59% (95% CI, 0.39 to 0.80%), which was significantly worse than any other lane change combination.
Conclusion: Swimmers were advantaged or disadvantaged depending on the direction and lane in which they swam. The existence of a current is the only cause that we can propose to explain these findings. Since one of FINA's primary stated objectives is to provide fairness in competition, new policies are needed to prevent similar biases from occurring in the future.
(C) 2015 American College of Sports Medicine