Influence of a COVID-19 induced reduction in game time on the match activity profiles of elite Australian Rules Football players

Abstract

Assess the influence of a 20% reduction in game time on the volume and intensity of elite AF players’ match activity profiles. GPS technology was used to analyse the movement demands of 45 AF players from the same AFL club during 43 matches across the 2019 and 2020 seasons. GPS data were categorised into measures of volume (total match time [TMT] and total distance [TD]) and intensity (metres per minute [m.min-1], high-intensity running [HIR] distance and m.min-1 [>17 km·h-1], and very-high intensity running [VHIR] distance and m.min-1 [>23 km·h-1]). Volume decreased in 2020 with reductions in TMT (effect size [ES] ± 95% confidence interval [CI] = -1.8 ± 0.2; p < .001) and TD (ES = -1.8 ± 0.2; p < .001) overall, across all positional groups, and quarters. Intensity increased, evidenced by increases in HIR m.min-1 (ES = 0.3 ± 0.1; p < .001), and VHIR m.min-1 (ES = 0.3 ± 0.2; p = .006). HIR m.min-1 increased for midfielders (ES = 0.6 ± 0.3; p = .017). Defenders exhibited increases in HIR m.min-1 (ES = 0.2 ± 0.2; p = .007), and VHIR m.min-1 (ES = 0.4 ± 0.2; p = .010). Intensity of third quarters decreased at a greater rate in 2020 with reductions in m.min-1 (ES = -0.2 ± 0.1; p = .004) and HIR m.min-1 (ES = -0.2 ± 0.1; p = .037) compared to Q1. Systematic reductions in volume were found overall, across positional groups, and quarters. Average movement speed remained relatively stable overall, across quarters and positional groups. Increases in intensity were defined predominately by increases at high and very-high intensity speeds per minute, with defenders exhibiting the greatest increase in intensity and change to their match activity profiles. Longer quarter and three-quarter time breaks, and time between goals preserved intensity.