Contextual maximum speed: Assessing the day-to-day variation in maximal running speed in Australian rules football

Monitoring sprint distance is commonplace in Australian Rules football (ARF). Thresholds are programmed as a percentage of maximum speed (V max ), however day-to-day variation has not been considered. The aim of this study was to determine the day-to-day variation in V max , jump height, power, and strength in male, talent-identified ARF athletes. Twenty-three male, ARF athletes (age = 16.6 ± 0.64 years, height = 179.4 ± 9.1 cm, mass = 73.4 ± 8.4 kg) completed a countermovement jump, isometric mid-thigh pull, and 40-metre sprint on three occasions within a 7-day period, separated by 48-h recovery periods. Descriptive statistics, repeated measures ANOVAs, and general linear regressions were used to analyze the data. V max declined progressively ( ηP 2 = 0.586, CV = 5%) between session one (31.8 ± 1.5km⋅h −1 ), two (30.8 ± 1.2km⋅h −1 ), and three (30.0 ± 1.3km⋅h −1 ). No differences were observed for jump height (47.4 ± 5.0 cm), peak force (2981 ± 518N), or net peak force (2047 ± 444N⋅kg −1 ). Jump height, peak force, and net peak force did not predict V max in session 1, session 2, or session 3. Individual changes in V max exceeded 5% in 10 instances. The V max is outside the typical error for measurement and indicative of the variation in V max . The lack of predictive power demonstrated by strength and power variables is evidence of the technical considerations associated with sprinting. Practitioners should consider the variation in V max when monitoring training load in field sports. The variation suggests that programming thresholds based upon a single recording of V max may incorrectly describe the true amount of high-speed and sprint running completed.