Effects of the COVID-19 Pandemic on the Performance of Marathon Runners.

Analyzing the performance of marathon runners is a study of vital importance for optimizing athletes' results. The COVID-19 pandemic and its measures against its spread resulted in a drastic change in the way of life of most of the population, including athletes, who saw their training habits modified, in addition to the possible short-, medium-, and long-term consequences that infection with the new virus could cause in their health. This study analyzes through normality analysis, Kolmogorov-Smirnov, Chi-square tests, and the Wasserstein distance the finish times and paces of more than 900k athletes (filtered by age range and gender) in major marathons in different cities around the world to determine the effects of the pandemic on their performance. The analysis using the Wasserstein distance shows that the period of years with the most significant differences in race pace was 2019-2021 (pre- and postpandemic years) in practically all the marathons analyzed, while the analysis using chi-square shows differences in that period of years in some cities, age, and gender groups. We found significant differences between 2019 and 2021 in pace behavior in some age and gender groups, shown by the Wasserstein distance and chi-square test.