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 (( ν ) (La.max)) and a modified formula of pure ( ν ) (La.max) (P( ν ) (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 ( ν ) (La.max) and three energy contributions (phosphagen, W (PCr); glycolytic, W (Gly); and oxidative, W (Oxi)). The P( ν ) (La.max) calculation considered delta La(−), time until W(peak) (t(PCr−peak)), and the time contributed by the oxidative system (t(Oxi)). Other ( ν ) (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); ( ν ) (La.max) (t(PCr −3.5%)) was significantly higher than P( ν ) (La.max) and ( ν ) (La.max) (t(PCr−peak)), while ( ν ) (La.max) (t(PCr−peak)) was lower than P( ν ) (La.max) (p < 0.0001, respectively). P( ν ) (La.max) and ( ν ) (La.max) (t(PCr−peak)) were highly correlated (r = 0.99; R ( 2 ) = 0.98). This correlation was higher than the relationship between P( ν ) (La.max) and ( ν ) (La.max) (t(PCr −3.5%)) (r = 0.87; R ( 2 ) = 0.77). ( ν ) (La.max) (t(PCr−peak)), P( ν ) (La.max), and ( ν ) (La.max) (t(PCr −3.5%)) were found to correlate with absolute W(mean) and W (Gly). Conclusion: P( ν ) (La.max) as a modified calculation of ( ν ) (La.max) provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ( ν ) (La.max) (t(PCr−peak)) and ( ν ) (La.max) (t(PCr −3.5%)). Because W (Oxi) and W (PCr) can differ remarkably between athletes, implementing their values in P( ν ) (La.max) can establish more optimized individual profiling for elite track cyclists.