TWO TESTS ARE NECESSARY TO DETERMINE MAXIMAL LACTATE STEADY STATE
Yaeger, D. B., White, R. F., & Stavrianeas, S. (2007). Determination of maximal lactate steady state: Convenience over accuracy? ACSM Annual Meeting New Orleans, Presentation Number, 1601.
This study evaluated if a two-test approach is necessary for a very precise determination of maximal lactate steady state. Aerobically trained Ss (N = 5) performed five exercise tests on a cycle ergometer. In the first test, participants performed an incremental VO2max test, and the lactate deflection point was identified as visual deflection from baseline. The second test consisted of six incremental stages ranging in intensity from 30 W below to 20 W above the predetermined deflection point. The maximal lactate steady state was identified from this second test, and verified through three randomized 45-minute steady-state exercise bouts at 95%, 100%, and 105% of the intensity identified as the maximal lactate steady state, and workloads never varied by more than 15 W from the maximal lactate steady state intensity. Blood lactate and oxygen consumption were measured.
The lactate deflection point obtained from the first test differed by 14 W from the maximal lactate steady state determined by the second test. The results of the prolonged bouts indicated that the maximal lactate steady state was identified correctly by the second test, as blood lactate levels remained constant throughout the 100% and 105% maximal lactate steady state bout, whereas lactate values were significantly different for the 95%.
Implication. Despite the greater convenience it offers, the determination of maximal lactate steady state from a single incremental test may underestimate the maximal lactate steady state intensity. The use of a second, more specific test is required for a precise identification of maximal lactate steady state.