LAUSR

OBJECTIVES The purpose of this study was to estimate between and within-athlete variabilities, to form threshold values for interpreting changes in locomotor activity in a female junior international hockey team. DESIGN Thirty-three female international hockey players (age: 20 ± 0.9 year; height: 166.1 ± 4.4 cm; body mass: 62.5 ± 6.2 kg) competed in thirty-four junior international hockey games.. METHODS Data were monitored through global positioning system technology. Locomotor activity was quantified as relative distances covered by players for each quarter at three speed zones (<16 km/h, 16-19.9 km/h, >20 km/h). Data were analysed using linear mixed models, accounting for the fixed effects of position (defenders, n = 13; midfielders, n = 8; forwards, n = 12), game result, type, location, and opposition rank. Variabilities are summarised as coefficients of variation (%CV). RESULTS Variabilities in athletes' game-to-game and quarter-to-quarter locomotor activity differed substantially between lower (<16 km/h) and higher (16-19.9 km/h and >20 km/h) speed zones. Game-to-game variability of low-speed movement (<16 km/h) was 5%; whereas, corresponding variabilities for high- (16-19.9 kmh) and very high-speed (>20 km/h) running were 22% and 34%, respectively. Within-athlete quarter-to-quarter variability increased for each speed zone, and was greatest for midfielders in low-speed movement and for defenders in high and very high-speed running. CONCLUSIONS The game-to-game variabilities inform thresholds for estimating changes in performance over time. Caution is required when interpreting such data, and coaches should carry out estimates in their specific contexts. Additionally, quarter-to-quarter variabilities in high- and very high-speed running for junior international hockey players outline position specific differences informing training practices to better prepare players for game demands.