Comparison of Modelled Maximal Lactate Steady State with Critical Power in Elite Cyclists

The aim of the current study was to compare modelled maximal lactate steady state with the field-based assessment of critical power in a group of highly trained pro cyclists. As a secondary objective, the relationships of the maximal rate of blood lactate accumulation and maximal oxygen consumption with outdoor maximal mean power output of different durations were explored. Twelve highly trained male professional cyclists performed six successive maximal tests. The maximal lactate steady state was calculated using the maximal rate of blood lactate accumulation, maximal oxygen consumption, resting oxygen uptake and body mass as input parameters. The critical power was estimated using the 3-minute and 20-minute maximal mean power outputs. The mean of the modelled maximal lactate steady state was 357±30.6 W, while the mean of critical power was 364±21.5 W; the modelled maximal lactate steady state and critical power correlated significantly (r=0.881 and p<0.001). The maximal oxygen consumption correlated with the 3-minute maximal mean power (r=0.646 and p=0.023), 20-minute maximal mean power (r=0.846 and p<0.001) and critical power (r=0.858 and p<0.001). No significant correlations were found between maximal rate of blood lactate accumulation and any of the outdoor maximal mean power outputs. The modelled maximal lactate steady state seems to predict critical power well on a group level; however, a substantial individual variation in the difference between the modelled maximal lactate steady state and critical power was observed. This individual variation would argue against conceptual similarity between the critical power and maximal lactate steady state model, which practitioners working within cycling should be aware of.