Lactate accumulation rate is associated with lactate turnpoints in cyclists and triathletes: a comparison of vLapeak and vLamaxblood

Purpose This study examined whether peak lactate accumulation rate ( v Lapeak) was associated with body-mass-normalised power at the first and second lactate turnpoints (LT1 rel and LT2 rel ) beyond relative maximal oxygen uptake (relative V̇O 2max ) and gross efficiency in cyclists and triathletes. Parallel models using maximal blood lactate accumulation rate ( v Lamax blood ) assessed whether the findings depended on the calculation approach. Methods 182 cyclists and triathletes (107 men, 75 women) completed a 15-s sprint test, an incremental lactate profile, and a ramp test to exhaustion. Hierarchical linear regression models included relative V̇O 2max and gross efficiency before adding either v Lapeak or v Lamax blood . Sex and sex × predictor interactions were examined exploratorily. Results Models including relative V̇O 2max , gross efficiency, and v Lapeak explained 75.3% of the variance in LT1 rel and 80.4% in LT2 rel . Adding v Lapeak increased explained variance by 4.9 and 5.0% points, respectively (both p < 0.001). Higher v Lapeak was associated with lower LT1 rel (B = − 0.803, 95% confidence interval − 1.070 to − 0.536) and LT2 rel (B = − 0.900, 95% confidence interval − 1.165 to − 0.635), whereas relative V̇O 2max and gross efficiency were positively associated with both outcomes. The v Lamax blood models showed the same direction and significance with similar fit. Sex and sex × predictor interactions did not improve the models. Conclusion Body-mass-normalised lactate turnpoint power reflects variation in aerobic power and efficiency as well as in the sprint-induced lactate accumulation response. Comparable findings for v Lapeak and v Lamax blood indicate that the associations were largely independent of whether the estimated alactic time interval was included in the calculation.