Applicability of VO2max criteria : discontinuous versus continuous protocols

This study compared the classic discontinuous Taylor et al. (1955) protocol to a continuous version of the same protocol to evaluate maximal physiological responses, and the quantitative values and incidence of achievement of the various maximal oxygen uptake (VO 2max ) criteria in 10 males (24.1 ± 2.5 yr). Criteria were a plateau in VO 2 (change 8 mmol.l -1 . Values for VO 2max (56.8 ± 4.7 vs 55.8 ± 4.2 ml.kg -1 .min -1 ), ventilation (150.7 ± 16 vs 149.5 ± 17.5 l.min -1 BTPS), and HR (186.3 ± 7.7 beats.min -1 vs 191.7 ± 6.7 beats.min -1 ) were similar (P > 0.05) between the discontinuous protocol (DT) and the continuous protocol (CT), respectively. Values for RER (1.28 ± 0.05 vs 1.22 ± 0.05) and lactate (14.3 ± 2.7 vs 11.9 ± 2.7 mmol.l -1 ) were greater (P < 0.05) on the DT than the CT. Criteria achievement were the following: 40% (CT) and 10% (DT) for HR; 50% (CT) and 60% (DT) for a VO 2 plateau; and, 90% (CT) and 100% (DT) for RER and lactate. It is concluded that a VO 2 plateau is not a prerequisite for defining VO 2max and is of limited use as the primary objective criterion for evaluating the quality of a graded exercise test. Therefore, the achievement of secondary objective criteria, specifically RER and lactate in combination, increases the likelihood that the highest VO 2 value achieved is VO 2max .