Purpose: To assess the concurrent and predictive validity of the 3-minute all-out test (3MT) against conventional methods (CM) of determining critical speed (CS) and curvature constant (D′) and to examine the test–retest reliability of the 3MT in highly trained swimmers. Methods: Thirteen highly trained swimmers (age 16 [2] y, weight 64.7 [8.5] kg, height 1.76 [0.07] m) completed 4 time trials and two 3MTs over 2 wk. The distance–time (DT) and speed–1/time (1/T) models were used to determine CS and D′ from 4 time trials. CS3MT and
Piatrikova, Gonzalez, and Williams are with the Dept for Health, University of Bath, Bath, United Kingdom. Sousa is with the Research Center for Sports, Exercise and Human Development, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal, and the University Inst of Maia, ISMAI, Maia, Portugal.