Performance indices selection for assessing anaerobic power during a 30 second vertical jump test

Aim. The aim of the present study was to assess the validity of jump height (h), absolute (VPOWER_ABS) and relative to body mass (VPOWER _REL) performance indices when elicited of a modified 30 s Bosco vertical jump test VJT based on the absolute (WPOWER_ABS) and relative (WPOWER_REL) power values of a 30 s Wingate test (WAnT). Methods. Nineteen physical education students with mean ± SD age 21 ±3 y, body mass 73.8±7 kg and height 1.8±0.06 m performed a 30 s VJT on a force plate and a 30 s WAnT on a Monark cycle ergometer. Performance data were expressed in W and W.kg^-1 of body mass for WPOWER_ABS and WPOWER_REL; in cm, W and W.kg^-1 for h, VPOWER_ABS and VPOWER_REL, respectively. The performance indices' values were expressed as means and SDs of the 30 s duration of both tests, as well as in 4 time intervals of 7.5 s (0-7.5 s, 7.5-15 s, 15-22.5 s, and 22.5-30 s). Results. WPOWER_ABS and h were significantly (P<0.05) correlated in the 4 time intervals (0-7.5 s: r=0.51; 7.5-15 s: r=0.36; 15-22.5 s: r=0.39) and in the overall duration of the test (0-30 s: r=0.38). Significant correlation was also revealed between VPOWER_ABS and WPOWER_ABS, but only for the interval 0-7.5 s (r=0.48). Conclusion. A 30 s VJT is valid against a 30 s WAnT only when h is used as performance indices. The selection of the appropriate unit of measurement is important for assessing effort distribution in maximum effort tests of short duration.