Pacing behaviour of middle-long distance running & race-walking athletes at the IAAF U18 and U20 World Championship finals

The current study analysed the pacing behaviour of athletes competing in the middle-long track eventfinals of the IAAF Under 18 and Under 20 World Championships between 2015 and 2018. Officialfinishing times, 1000-m split times and positioning data of 116 female and 153 male athletes, competingin the middle-long distance running (3000 m, 5000 m and 10,000 m) and race walking (5000 m and10,000 m) events, were gathered. Repeated measures analysis of variance, with 1000-m speed as within-subjects factor and final ranking (medallist, Top 8 or Top 12, rest of the field) as between-subjectsfactor, was performed to compare the pacing behaviour between athletes. Positioning of the athleteswas analysed by Kendall tau-b (Tb) correlation between the intermediate position and final position.Overall, medallists increased their speed throughout a race, with the exception of the 5000 m runningevent, in which a parabolic pacing behaviour was exhibited. The 1000-m segment in which a significant(P > 0.05) difference in speed was exhibited between differently ranked athletes coincided with a strong(Tb > 0.7) correlation between intermediate and final positioning. These combined results point towardsa separation between the athletes during the race, as the Top 8 or Top 12 and the rest of the field areunable to match the speed of the medallists. The distance, discipline, sex, age category and behaviourof competitors all influence the pacing behaviour of young track athletes during international levelcompetition, emphasising the importance and complexity of developing adequate pacing behaviour intrack athletes.