Comparison of Selected Lactate Threshold Parameters with Maximal Lactate Steady State in Cycling

Abstract

The aim of the present investigation was to compare power at "onset of blood lactate accumulation" (OBLA), "individual anaerobic threshold" (IAT) and "+1.5 mmol ∙ l(-1) lactate model" with power in maximal lactate steady state (MLSS) in cycling. However, there is a lack of studies concerning the absolute individual differences between different lactate parameters and MLSS.A total of 57 male participants performed several 30-min constant-load tests to determine MLSS by measuring blood lactate concentration (BLC). Depending on BLC, power was increased or decreased by 10 W in the following 30-min test. For detecting power at different threshold parameters, an incremental test was performed that began at 40 W and increased by 40 W every 4 min.Highly significant correlations were found between OBLA and MLSS: r=0.89 (mean difference -7.4 W); IAT and MLSS: r=0.83 (mean difference 12.4W), "+1.5 mmol ∙ l(-1) lactate model" and MLSS: r=0.88 (mean difference -37.4W). On average, the parameters of OBLA and IAT approximate MLSS with no significant differences. The "+1.5 mmol ∙ l(-1) lactate model" underestimates MLSS significantly.Based on Bland-and-Altman, the comparison of power of all threshold parameters with power in MLSS shows great individual differences despite the high regression coefficients and low mean differences between these methods.