Determination of Critical Power Using a 3-min All-out Cycling Test


Medicine & Science in Sports & Exercise:
doi: 10.1249/mss.0b013e31802dd3e6
APPLIED SCIENCES: Physical Fitness and Performance

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.

Author Information

1Department of Sport and Exercise Science, University of Wales, Aberystwyth, UNITED KINGDOM; and 2Chelsea School Research Centre, University of Brighton, Eastbourne, UNITED KINGDOM

Address for correspondence: Mark Burnley, Department of Sport andExercise Science, Carwyn James Building, University of Wales, Aberystwyth, Aberystwyth, Ceredigion, SY23 3FD, UK; E-mail:

Submitted for publication August 2006.

Accepted for publication November 2006.

©2007The American College of Sports Medicine