Maximal lactate steady state determination with a single incremental test exercise

The aim of this study was to determine whether the power output associated with a maximal lactate steady state (MLSS) ((W)over dot(MLSS)) can be assessed using a single incremental cycling test. Eleven recreational sportsmen (age: 22 +/- 1 years, height: 175 +/- 6 cm, weight: 71 +/- 5 kg) volunteered to participate in the study. For each subject the first and second ventilatory thresholds (VT(1) and VT(2), respectively) and the power output corresponding to (respiratory exchange ratio) RER=1.00 were determined during an incremental test to exhaustion. Thereafter, each subject performed several 30-min constant load tests to determine MLSS. The workload used in the first constant test was set to the (W)over dot(RER=1.00) determined during the incremental test. (W)over dot(VT1) (175 +/- 24 W) and (W)over dot(VT2) (265 +/- 31 W) were significantly different from (W)over dot(MLSS) (220 +/- 36 W). Whereas, (W)over dot(RER=1.00) (224 +/- 33 W) was similar to (W)over dot(MLSS). HR, RER and VE were significantly different between the 10th and the 30th minutes when exercising at (W)over dot(RER=1.00) and at (W)over dot(MLSS). In contrast, (V)over dotO(2) and (V)over dotCO(2) were stable over those 30-min constant tests. Power output at VT(1), RER=1.00 and VT(2) were all correlated to (W)over dot(MLSS) but the relationship was stronger between RER=1.00 and MLSS (R(2)=0.95). The present study shows that the power output associated with a RER value equal to 1.00 during an incremental test does not differ from that determined for MLSS. Hence, the MLSS can be estimated with a single exercise test.