The reliability and validity of the T-test as a measure of leg power, leg speed, and agility were examined. A total of 304 college-aged men (n = 152) and women (n = 152), selected from varying levels of sport participation, performed 4 tests of sport skill ability: (a) 40-yd dash (leg speed), (b) counter-movement vertical jump (leg power), (c) hexagon test (agility), and (d) T-test. For both men and women, significant differences (p < 0.05) in mean scores were found among groups for the T-test. The intraclass reliability of the T-test was 0.98 across 3 trials. For men, the Pearson product moment correlations between the T-test and the 40-yd dash, vertical jump, and hexagon test were r = 0.53, r = -0.49, and r = 0.42, respectively (p < 0.05). For women, the corresponding correlations were r = 0.73, r = -0.55, and r = 0.48 (p < 0.05). Regression analyses showed that for men 48% of the variability and for women 62% of the variability of the T-test scores can be predicted from measures of leg power, leg speed, and agility (p < 0.05). Computing partial correlations assessed the criterion validity of the T-test as a measure of agility, leg power, and leg speed. The T-test appears to be highly reliable and measures a combination of components, including leg speed, leg power, and agility, and may be used to differentiate between those of low and high levels of sports participation.
(C) 2000 National Strength and Conditioning Association