A comparative analysis of two novel shuttle running field tests for critical velocity modelling in football players

Background and aim: The study compared differences in derived critical velocity (CV) and maximal speed from the 3-Minute All-Out Shuttle Test (3MST), 7-Minute Intermittent Critical Velocity Shuttle Test (7MST) and 3-Minute All-Out Running Test (3MRT). We also determined test-retest reliability of the 3MST versus the 7MST. Methods: Eleven semi-professional football players completed 10 visits; 3 familiarisation and 7 testing sessions (3 trials for each of the 3MST and 7MST and 1 trial of the 3MRT). CV was calculated, and maximal speed was recorded via GPS. Results: CV via the 3MRT (14.17 ± 1.49 km.h-1) was faster than the 3MST (10.12 ± 0.97 km.h-1, p < 0.001) and 7MST (9.03 ± 0.97 km.h-1, p < 0.001), although minimal differences were observed between the 3MST and 7MST (p = 0.13). Maximal speed differed across all test modes; 3MRT (29.07 ± 2.19 km.h-1, p < 0.001), 3MST (26.18 ± 1.71 km.h-1, p < 0.001) and 7MST (23.14 ± 1.10 km.h-1, p < 0.001). Intra-class correlation coefficient was larger for the 3MST (0.37) than the 7MST (0.05). Coefficient of variation was smaller for the 3MST (7.57%) compared to the 7MST (11.56%). Conclusions: Shuttle tests derive significantly slower CV and maximal speeds compared to linear tests and thus likely provide greater task specificity for CV modelling of team-sport athletes.