Effect of performance standard and sex on 24 h ultra-marathon pacing profiles

The purpose of the present study was to examine the effect of sex and performance standard on pacing profiles in a 24 h ultra-marathon race. Performance data of 283 participants (237 men and 46 women) from the last decade’s versions (2011 until 2020, with the exception of the 2017 version) of the International Ultramarathon Festival held in Athens-Hellinikon, Greece, were analyzed and pacing profiles were evaluated based on performance standard and sex. Relative speed for every hour and % distance covered in 6 h and 12 h segments and coefficient of variation (CV) were calculated. Mean distance ran was 159.99±36.04 km. Runners followed a reverse J-shaped race pace ( p < 0.001). Sex did not seem to interact with pacing ( p > 0.05 in every case), while performance standard interacted significantly with pacing ( p < 0.001). CV was negatively correlated with total distance covered and total running time (–0.761, p < 0.001 and –0.753, p < 0.001, respectively). In conclusion, the overall pacing profile adopted by runners in a 24 h ultra-marathon race was a reverse J-shaped model, with better runners following a more even pacing than slower runners, with lower velocity variability.