Fig. 2

Oxygen uptake (V̇O₂) responses to an incremental test followed by a multistage verification phase for two representative subjects. a represents a valid test, while b represents a test were verification phase maximal oxygen uptake (V̇O_2max) was higher than that reached during incremental phase, consequently, an invalid test. Note: differences between phases were considered as V̇O₂ differences > 2%; > 3%; > 2.2 or 2.0 ml kg⁻¹ min⁻¹ and V̇O₂ values presented as 15-s averages