Comparison of a Countermovement Jump Test and Submaximal Run Test to Quantify the Sensitivity for Detecting Practically Important Changes Within High-Performance Australian Rules Football

The purpose of this study was to determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football (ARF) players. 23 professional and semi-professional ARF players, performed six CMJs and three, eight-second 50-meter runs every 30 s (SRT), seven days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation (CV) ± 90% confidence intervals (CI). Test-retest reliability was examined using the magnitude of the difference (effect size (ES) ± 90% CI) from week 1 to week 2. The smallest worthwhile change (SWC) was calculated as 0.25 x SD. Good reliability (CVs = 6.6 - 9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV < SWC, indicating an ability to detect practically important changes in performance. Only peak velocity from the CMJ test possessed a CV < SWC, exhibiting a limitation of this test in detecting practically meaningful changes within this environment. The results suggest that while all variables possess acceptable reliability, a SRT might offer to be a more sensitive monitoring tool than a CMJ test within high-performance ARF, due to its greater ability for detecting practically important changes in performance.