Measuring VO2max in adolescents: verification phase and impact of time averaging strategies

An oxygen uptake (V̇O2) plateau, despite an increased work rate, is considered the gold standard for confirming if exercise test performance reflects maximal oxygen uptake (V̇O2max). We investigated whether adolescents demonstrate a V̇O2 plateau during an incremental test or if a supramaximal verification phase is necessary to confirm V̇O2max. We also investigated the impact of using moving versus binned time averages on V̇O2max values, and how these time averaging strategies influence the interpretation of the verification phase in confirming V̇O2max. A total of 27 adolescents (16 girls) aged 12 to 14 years completed an incremental cycle ergometer ramp test to exhaustion. After a 15-minute recovery, a verification phase was conducted at 105% of their incremental test peak power. V̇O2max was analysed using 15-second binned and moving averages. Out of 27 participants, 5 (19%) demonstrated a plateau in V̇O2 during an incremental test. V̇O2max was confirmed in the verification phase for 23 out of the 27 adolescents (85%). The moving V̇O2max (mL/kg/min) averages were higher than the binned V̇O2 values in the incremental test (1.8%) and the verification phase (2.4%) (P < 0.0001). Time averaging strategies did not affect the confirmation of V̇O2max. A verification phase is necessary for accurately determining V̇O2max in adolescents, who often do not reach a V̇O2 plateau. The time averaging strategies of exercise tests should be reported, as different strategies can lead to variations in V̇O2max results. However, these time averaging strategies do not impact the utility of the verification phase.