Determination of critical power using a 3-min all-out cycling test

VANHATALO, A., J. H. DOUST, and M. BURNLEY. Determination of Critical Power Using a 3-min All-out Cycling Test. Med. Sci. Sports Exerc., Vol. 39, No. 3, pp. 548-555, 2007. Purpose: We tested the hypothesis that the power output attained at the end of a 3-min all-out cycling test would be equivalent to critical power. Methods: Ten habitually active subjects performed a ramp test, two 3-min all-out tests against a fixed resistance to establish the end-test power (EP) and the work done above the EP (WEP), and five constant work rate tests to establish the critical power (CP) and the curvature constant parameter (W) using the work-time and 1/time models. Results: The power output in the 3-min trial declined to a steady level within 135 s. The EP was 287 55 W, which was not significantly different from, and highly correlated with, CP (287 +/- 56 W; P = 0.37, r = 0.99). The standard error for the estimation of CP using EP was approximately 6 W, and in 8 of 10 cases, EP agreed with CP to within 5 W. Similarly, the WEP derived from the 3-min test (15.0 +/- 4.7 kJ) was not significantly different from, and correlated with, W (16.0 +/- 3.8 kJ; P = 0.35; r = 0.84). Conclusions: During a 3-min all-out cycling test, power output declined to a stable value in approximately the last 45 s, and this power output was not significantly different from the independently measured critical power.