Montgomery, PG, and Wisbey, B. The effect of interchange rotation period and number on Australian Football running performance. J Strength Cond Res 30(7): 1890-1897, 2016-To determine the effect of on-field rotation periods and total number of game rotations on Australian Football running performance, elite Australian Football players (n = 21, mean ± SD; 23.2 ± 1.7 years; 183.5 ± 3.7 cm; 83.2 ± 4.5 kg) had Global Positioning System game data from 22 rounds divided into a total of 692 on-field playing periods. These periods were allocated into time blocks of 2:00-minute increments, with the log transformed percentage differences in running performance (m·min) between blocks analyzed by effect size and meaningful differences. A total of 7,730 game rotation and associated average m·min combinations collected over 3 Australian Football seasons were also assessed by effect size and meaningful differences. Running capacity decreases after 5:00 minutes by ∼3% for each 2:00 minutes of on-field time up to 9:00 minutes, with variable responses between positions up to 6.7% for nomadic players. For each rotation less than 6 per game, clear small-to-moderate decreases up to 3.6% in running capacity occurred per rotation. To maintain a high level of running capacity, shorter on-field periods are more effective in Australian Football; however, players and coaches should be aware that with interchange restriction, slightly longer on-field periods achieve similar results.