The interaction of competition and terrain on pacing during cross-county running races in junior athletes

The aim of this study was to assess pacing during cross-country racing in relation to race length, surface-terrain and racing dynamics. Athletes (n = 148) competed for school teams (U15, U17, U20) over 2.9, 4.2, 6.3 km, respectively. The course lap (2.067 m) was timed using UHF-RFID and divided into six sections based on surface-terrain and length (549, 619, 207, 338, 150, 156m). Overall pace differed between races (4.56 ± 0.30, 4.42 ± 0.38, 4.40 ± 0.31 m∙s−1, p=0.042) but not for the top-20 of each race (p=0.174). Moreover, within lap pacing followed a repeated reverse-“J”-parabolic strategy for all races. Race length (no. of laps) and category affected pacing with regards to finish position banding (1st–10th, 11th–20th) where effect size differences showed large to extremely large (1.21– >4.00) difference between top-10 and other bands. Exceptions to this included the finish sprint where it was typically trivial-moderate (<0.2–1.2) and in key areas where social facilitation occurred. Athlete/coaches need to be aware of between and within lap variations in pace/effort, the effects of race dynamics, and spectator influences, while all athletes need to be educated as part of their training to run their own optimal strategy for best performance.