A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate (( ? ) (La.max)) and a modified formula of pure ( ? ) (La.max) (P- ? (La.max)) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships.Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (W-peak and W-mean), oxygen uptake, and blood lactate concentrations (La-) were measured. These parameters were used for different calculations of ( ? ) (La.max) and three energy contributions (phosphagen, W (PCr); glycolytic, W (Gly); and oxidative, W (Oxi)). The P- ? (La.max) calculation considered delta La-, time until W-peak (t(PCr-peak)), and the time contributed by the oxidative system (t(Oxi)). Other ( ? ) (La.max) levels without t(Oxi) were calculated using decreasing time by 3.5% from W-peak (t(PCr -3.5%)) and t(PCr-peak).Results: The absolute and relative W (PCr) were higher than W (Gly) and W (Oxi) (p < 0.0001, respectively), and the absolute and relative W (Gly) were significantly higher than W (Oxi) (p < 0.0001, respectively); ( ? ) (La.max) (t(PCr -3.5%)) was significantly higher than P- ? (La.max) and ( ? ) (La.max) (t(PCr-peak)), while ( ? ) (La.max) (t(PCr-peak)) was lower than P- ? (La.max) (p < 0.0001, respectively). P- ? (La.max) and ( ? ) (La.max) (t(PCr-peak)) were highly correlated (r = 0.99; R ( 2 ) = 0.98). This correlation was higher than the relationship between P- ? (La.max) and ( ? ) (La.max) (t(PCr -3.5%)) (r = 0.87; R ( 2 ) = 0.77). ( ? ) (La.max) (t(PCr-peak)), P- ? (La.max), and ( ? ) (La.max) (t(PCr -3.5%)) were found to correlate with absolute W-mean and W (Gly).Conclusion: P- ? (La.max) as a modified calculation of ( ? ) (La.max) provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ( ? ) (La.max) (t(PCr-peak)) and ( ? ) (La.max) (t(PCr -3.5%)). Because W (Oxi) and W (PCr) can differ remarkably between athletes, implementing their values in P- ? (La.max) can establish more optimized individual profiling for elite track cyclists.