Lactate response to short term exercise with elevated starting levels

A model that describes the blood lactate concentration (BLC) dynamics [BLC(t)] of a Wingate Anaerobic Test (WAnT) as a function of (a) BLC at the start of exercise (BLC₀), (b) extra-vascular increase in lactate (A), (c) two corresponding velocity constants of appearance (k ₁) and disappearance (k ₂) of lactate into and out of the blood requires that BLC₀ is equal to resting BLC (BLC_rest). We developed a model that considers an elevated BLC₀. 19 males performed WAnTs with warm-ups increasing (p < 0.001) BLC₀. The goodness of each individual fit improved (p < 0.05) if the difference between BLC_rest and BLC₀ (ΔBLC) was higher than 1.0 mmol l⁻¹. All differences between old and new model (p < 0.05) in A, k ₁ and k ₂ were interrelated with and increased with ΔBLC (p < 0.05). The new model well describes BLC(t) and prevents substantial errors concerning lactate generation and dynamics if BLC₀ is elevated by more than 1.0 mmol l⁻¹.