Maximal Lactate Steady State's Dependence on Cycling Cadence

The maximal lactate steady state (MLSS) depicts the highest blood lactate concentration (BLC) that can be maintained over time without a continual accumulation at constant prolonged workload. In cycling, no difference in the MLSS was combined with lower power output related to peak workload (I-MLSS) at 100 than at 50 rpm. MLSS coincides with a respiratory exchange ratio (RER) close to 1. Recently, at incremental exercise, an RER of 1 was found at similar workload and similar intensity but higher BLC at 100 than at 50 rpm. Therefore, the authors reassessed a potential effect of cycling cadences on the MLSS and tested the hypothesis that the MLSS would be higher at 105 than at 60 rpm with no difference in I-MLSS in a between-subjects design (n=16, age 25.1 +/- 1.9 y, height 178.4 +/- 6.5 cm, body mass 70.3 +/- 6.5 kg vs n=16, 23.6 +/- 3.0 y, 181.4 +/- 5.6 cm, 72.5 +/- 6.2 kg; study I) and confirmed these findings in a within-subject design (n=12, 25.3 +/- 2.1 y, 175.9 +/- 7.7 cm, 67.8 +/- 8.9 kg; study II). In study I, the MLSS was lower at 60 than at 105 rpm (4.3 +/- 0.7 vs 5.4 +/- 1.0 mmol/L; P=.003) with no difference in I-MLSS (68.7%+/- 5.3% vs 71.8%+/- 5.9%). Study II confirmed these findings on MLSS (3.4 +/- 0.8 vs 4.5 +/- 1.0 mmol/L; P=.001) and I-MLSS (65.0%+/- 6.8% vs 63.5%+/- 6.3%; P=.421). The higher MLSS at 105 than at 60 rpm combined with an invariance of I-MLSS and RER close to 1 at MLSS supports the hypothesis that higher cadences can induce a preservation of carbohydrates at given BLC levels during low-intensity, high-volume training sessions.