Table 1.

Articles evaluating the agility factorial structure or change of direction

Authors	Participants	Tests performed	Statistics	Result
Stewart et al., 2014	n = 44, 24 males, 20 females, Age: 16.7 ± 0.6 years, College* (invasive games)	Illinois L-Run Pro-Agility T-test 5-0-5 agility	PCA, Kaiser-Guttman criterion	The PCA resulted in the extraction of one significant component that explained 89.52% of the total variance. All selected tests were positively and strongly correlated (r = 0.84–0.89). It was concluded that all tests were highly reliable and valid measures of CODS.
Salaj and Markovic, 2011	n = 87, male college athletes, Age: 19.3 ± 1 years	Skinfold thickness SJ, CJ, SLJ, LS Sprint 5 m, 10 m Sprint 20 m Flying sprint 20 m 18-m shuttle run Figure-of-eight run DJ 30, 50 cm Maximal hopping in place – 6 rebounds	PCA, Kaiser-Guttman criterion	The PCA revealed a relatively simple and consistent structure consisting of 4 separate factors that explained nearly 80% of the variance of the applied tests. The factors appeared to correspond to the sprinting ability, concentric/slow SSC jumping ability, fast SSC jumping ability and CODS ability.
Markovic et al., 2007	n=168, male * Age: 21±2 years	18.3-m shuttle run Slalom run SJ, CJ, SLJ, LS DJ 30, 50 cm Isometric Sq, lRM back Sq Weighted Sq jump force Maximal hopping in place – 5 rebounds	EFA, regression analysis	Factor analysis of all tests revealed four independent factors: explosive strength, elastic strength, CODS and maximal strength. The regression analysis revealed significant multiple correlation between predictors and the criterion (R=0.41; p<0.001); the amount of explained variance of the agility performance by the strength factors was low (17%). Leg extensor strength qualities are poor predictors of agility performance.
Sporis et al., 2010	n=150, Male, elite junior soccer players, Age: 19.1 ± 0.6 years	Slalom test CODS sprint 4×5 m T test Sprint with 90° turns Sprint with 180° turns SBF	PCA, Kaiser-Guttman criterion	It was concluded that of the 6 agility tests used in this study, the SBF, T-test, and Sprint with 180° turns were the most reliable and valid tests for estimating agility of soccer players. PCA resulted in the extraction of two significant components that explained 56.99% of the total variance. SBF test (r = 0.78) had the best factorial validity among all analyzed agility tests, and comparable factorial validity was observed for the T-test (r = 0.73) and Sprint with 180° turns (r = 0.73) test.

CODS = change of direction speed, *physical education student, 1RM = one repetition maximum, SSC = stretch shortening cycle, CJ = countermovement jump, SLJ = standing long jump, SJ = squat jump, DJ = drop jump, LS = lateral stepping, Sq = squat, SBF = sprint with backward and forward running, PCA = principal component analysis, EFA = factor analysis - exploratory approach