Assessment of Critical Power with Children

The purpose of this study was to examine methods of assessing Critical Power (CP) with children. Eight boys and 9 girls (10.3 – 0.4 yrs) completed 3 cycle tests in one day, each at a different constant power output predicted to induce fatigue in 2 to 15 min. Time to exhaustion was recorded, and order of the tests was randomized, with 3 hours recovery between tests. The children repeated these tests and 2 additional tests with at least 24 hr recovery between each test. CP was determined using least squares linear regression analysis of the power — t −1 relationship, for the single day (CP 1 ), the 5 tests from different days (CP 2 ), and the repeated 3 tests from different days (CP 3 ). The 95% limits of agreement (range of percentage differences) were −15.4 to 13.1% (CP 1 v CP 2 ), −16.8 to 13.5% (CP 1 v CP 3 ), and −8.4 to 6.7% (CP 2 v CP 3 ). CP is a robust measure even when only 3 tests are completed in a single day and may be used to provide a simple and useful parameter of exercise intensity for constant load exercise with children.