AbstractThe aim of the study was to evaluate and compare the maximal oxygen uptake ($\dot{\mathrm{V}}$ V ˙ O_2max) achieved during incremental and decremental protocols in highly trained athletes. Nineteen moderate trained runners and rowers completed, on separate days, (i) an initial incremental $\dot{\mathrm{V}}$ V ˙ O_2max test (INC) on a treadmill, followed by a verification phase (VER); (ii) a familiarization of a decremental test (DEC); (iii) a tailored DEC; (iv) a test with decremental and incremental phases (DEC-INC); (v) and a repeated incremental test (INC_F). During each test $\dot{\mathrm{V}}$ V ˙ O₂, carbon dioxide production, ventilation, heart and breath rates and ratings of perceived exertion were measured. No differences were observed in $\dot{\mathrm{V}}$ V ˙ O_2max between INC (61.3 ± 5.2 ml kg⁻¹ min⁻¹) and DEC (61.1 ± 5.1 ml kg⁻¹ min⁻¹; average difference of ~ 11.58 ml min⁻¹; p = 0.831), between INC and DEC-INC (60.9 ± 5.3 ml kg⁻¹ min⁻¹; average difference of ~ 4.8 ml min⁻¹; p = 0.942) or between INC and INC_F (60.7 ± 4.4 ml kg⁻¹ min⁻¹; p = 0.394). $\dot{\mathrm{V}}$ V ˙ O_2max during VER (59.8 ± 5.1 ml kg⁻¹ min⁻¹) was 1.50 ± 2.20 ml kg⁻¹ min⁻¹ lower (~ 2.45%; p = 0.008) compared with values measured during INC. The typical error in the test-to-test changes for evaluating $\dot{\mathrm{V}}$ V ˙ O_2max over the five tests was 2.4 ml kg⁻¹ min⁻¹ (95% CI 1.4–3.4 ml kg⁻¹ min⁻¹). Decremental tests do not elicit higher $\dot{\mathrm{V}}$ V ˙ O_2max than incremental tests in trained runners and rowers, suggesting that a plateau in $\dot{\mathrm{V}}$ V ˙ O₂ during the classic incremental and verification tests represents the maximum ceiling of aerobic power.