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

Abstract

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate (νLa.max) and a modified formula of pure νLa.max (PνLa.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 (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La−) were measured. These parameters were used for different calculations of νLa.max and three energy contributions (phosphagen, WPCr; glycolytic, WGly; and oxidative, WOxi). The PνLa.max calculation considered delta La−, time until Wpeak (tPCr−peak), and the time contributed by the oxidative system (tOxi). Other νLa.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr −3.5%) and tPCr−peak.Results: The absolute and relative WPCr were higher than WGly and WOxi (p < 0.0001, respectively), and the absolute and relative WGly were significantly higher than WOxi (p < 0.0001, respectively); νLa.max (tPCr −3.5%) was significantly higher than PνLa.max and νLa.max (tPCr−peak), while νLa.max (tPCr−peak) was lower than PνLa.max (p < 0.0001, respectively). PνLa.max and νLa.max (tPCr−peak) were highly correlated (r = 0.99; R2 = 0.98). This correlation was higher than the relationship between PνLa.max and νLa.max (tPCr −3.5%) (r = 0.87; R2 = 0.77). νLa.max (tPCr−peak), PνLa.max, and νLa.max (tPCr −3.5%) were found to correlate with absolute Wmean and WGly.Conclusion: PνLa.max as a modified calculation of νLa.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than νLa.max (tPCr−peak) and νLa.max (tPCr −3.5%). Because WOxi and WPCr can differ remarkably between athletes, implementing their values in PνLa.max can establish more optimized individual profiling for elite track cyclists.

Reliability of power output, maximal rate of capillary blood lactate accumulation, and phosphagen contribution time following 15‐s sprint cycling in amateur cyclists

“…t Ppeak-3.5% was calculated as the time from the start of the test until peak power was reached and subsequently decreased by 3.5% or more . Existing measures were employed to preclude the introduction of an additional time frame, with t Ppeak-3.5% being utilized to reflect the accuracy error of an early version of the SRM ergometer (Yang et al, 2023). Additionally, a fixed t PCr of 3.5 s was used for calculations.…”

“…Many test procedures and physiological variables exist to judge the aerobic and anaerobic metabolic components involved in high-intensity cycling. In recent years the post-exercise level of capillary blood lactate accumulation has received increasing interest in order to calculate the glycolytic capacity in cycling (Adam et al, 2015;Dunst et al, 2023;Yang et al, 2023), hand-cycling Quittmann et al, 2018) and other endurance sports including running (Quittmann et al, 2022;Quittmann, Appelhans, et al, 2020;, swimming (Mavroudi et al, 2023;Teixeira et al, 2022) and rowing (Schünemann et al, 2023). In this regard the peak accumulation of capillary blood lactate within 10 min after a 15-s all-out sprint (often abbreviated as νLa max ) has been widely discussed among athletes and within the coaching community as a feasible indicator to calculate the glycolytic capacity during sprint cycling (note: here νLa max is preferred over "ċLa max " due to its established recognition) (Heck & Schulz, 2002;Mader, 2003;Mader & Heck, 1986;Quittmann et al, 2022).…”

“…Short maximal efforts (such as 15-s sprint cycling) rely largely on the phosphocreatine pathway as well as glycolysis to regenerate ATP rapidly (Heck & Schulz, 2002;Nevill et al, 1994;Yang et al, 2023). Therefore, the ability to produce lactate quickly is considered one important predictor of sprint performance.…”

“…In situations where the requisite sampling rates for determining specific measures are not available, a practical duration of 3.5 seconds can be adopted, following the recommendations provided by Heck and Schulz (Heck & Schulz, 2002). Interestingly, although t PCr is a very important element in the formula its determination has not been discussed much (Dunst et al, 2023;Yang et al, 2023) and no thorough reliability investigation of the different t PCr exists so far. The process of calculating νLa max , which hinges on a foundation of physiological data, is subject to typical variability inherent in such measurements.…”

The Influence of Pedaling Frequency on Blood Lactate Accumulation in Cycling Sprints

“…When considering the methods used for maximal sprints on a cycle ergometer, there are differences in test mode (isokinetic, non-isokinetic with fixed load/breaking force), test duration (10 s, 15 s, 30 s) and pedaling frequency (120 rpm or 130 rpm in isokinetic mode, maximal in non-isokinetic mode) 4 6 14 20 21 22 . Understanding how these different methods influence the kinetics of glycolytic activity and the resulting changes in BLC is of significant interest for an accurate assessment of the maximal lactate formation rate (υLa max ).…”