A longitudinal study of the development of 1500-m performance and pacing behaviour in world-class youth short-track speed skaters.

The goal-directed distribution of velocity (i.e. pacing behaviour) is a key component in performance optimisation and safeguarding athlete wellbeing, especially in developing athletes (Elferink-Gemser & Hettinga, 2017, International Journal of Sports Physiology and Performance, 12(6), 831–835). Short-track speed skating features head-to-head races in a highly interactive environment, demanding skaters to incorporate decisions on drafting, overtaking and collision avoidance in their pacing behaviour. The aim of the current research was to, for the first time, longitudinally study the development of performance and pacing behaviour of elite youth short-track speed skaters. It was hypothesised that performance would gradually improve with age, paralleled with a development towards the more conservative pacing behaviour (Menting, Konings, Elferink-Gemser, & Hettinga, 2019, International Journal of Sports Physiology and Performance, 14(2), 222–231). Lap times were collected of elite short-track speed skaters performing in 1500-m races (13.5 laps) during Junior World Championships between 2010 and 2018 (141 skaters, 573 observations). The study was approved by the local ethical committee and in accordance with the Declaration of Helsinki. Included skaters had to perform in at least two or more different age categories between 15 and 20 (e.g. age category 15 included skaters of 14.5-15.5 years old). Races were divided into four sections (laps 1-3, laps 4-7, laps 8-11 and laps 12-14). Multilevel prediction models in which repeated measures (level-1) were nested within the individual skaters (level-2), were used to analyse the effect of age category on total race time, absolute section time (AST; time spend in a section) and relative section time (RST; percentage of total time spent in a section). Analyses were carried out using the MLwiN program (p<.05). The coefficient [standard error] of each model will be reported. Total race time decreased with age (-9.93s [1.98], p<0.01). Age did not affect the AST of laps 1-3 (-0.42s [1.06], p = 0.69) and laps 4-7 (-0.554s [0.72], p = 0.44). With increasing age, the AST of laps 8-11 (2.48s [0.43], p<0.01) and 12-14 (-3.04s [0.45], p<0.01) decreased. The RST of laps 1-3 increased with age (1.10% [0.49], p = 0.03). Vice versa, the RST of laps 12-14 decreased with age (-1.15% [0.38], p<0.01). No effect of age was found for the RST of laps 4-7 (0.48% [0.33], p = 0.15) and laps 8-11 (-0.35% [0.33], p = 0.29). With age, skaters increase their overall performance by developing a more conservative pacing behaviour, reserving energy during the start of the race, in order to increase their velocity in the second half of the race. These findings emphasize the importance of the adolescence phase in the development of performance and pacing behaviour in elite athletes.