Modelling the lactate response to short-term all out exercise

Ralph Beneke,Masen D Jumah,Renate M Leithäuser

doi:10.1186/1476-5918-6-10

Ralph Beneke, Masen D Jumah + Show 1 more

Open Access

https://doi.org/10.1186/1476-5918-6-10

Copy DOI

Abstract

BackgroundThe maximum post exercise blood lactate concentration (BLCmax) has been positively correlated with maximal short-term exercise (MSE) performance. However, the moment when BLCmax occurs (TBLCmax) is rather unpredictable and interpretation of BLC response to MSE is therefore difficult.MethodsWe compared a 3- and a 4-parameter model for the analysis of the dynamics of BLC response to MSEs lasting 10 (MSE10) and 30 s (MSE30) in eleven males (24.6 ± 2.3 yrs; 182.4 ± 6.8 cm; 75.1 ± 9.4 kg). The 3-parameter model uses BLC at MSE-start, extra-vascular increase (A) and rate constants of BLC appearance (k1) and disappearance (k2). The 4-parameter model includes BLC at MSE termination and amplitudes and rate constants of increase (A1, y1) and decrease (A2, y2) of post MSE-BLC.ResultsBoth models consistently explained 93.69 % or more of the variance of individual BLC responses. Reduction of the number of parameters decreased (p < 0.05) the goodness of the fit in every MSE10 and in 3 MSE30. A (9.1 ± 2.1 vs. 15.3 ± 2.1 mmol l-1) and A1 (7.1 ± 1.6 vs. 10.9 ± 2.0 mmol l-1) were lower (p < 0.05) in MSE10 than in MSE30. k1 (0.610 ± 0.119 vs. 0.505 ± 0.107 min-1), k2 (4.21 10-2 ± 1.06 10-2 vs. 2.45 10-2 ± 1.04 10-2 min-1), and A2 (-563.8 ± 370.8 vs. -1412.6 ± 868.8 mmol l-1), and y1 (0.579 ± 0.137 vs. 0.489 ± 0.076 min-1) were higher (p < 0.05) in MSE10 than in MSE30. No corresponding difference in y2 (0.41 10-2 ± 0.82 10-2 vs. 0.15 10-2 ± 0.42 10-2 min-1) was found.ConclusionThe 3-parameter model estimates of lactate appearance and disappearance were sensitive to differences in test duration and support an interrelation between BLC level and halftime of lactate elimination previously found. The 4-parameter model results support the 3-parameter model findings about lactate appearance; however, parameter estimates for lactate disappearance were unrealistic in the 4-parameter model. The 3-parameter model provides useful information about the dynamics of the lactate response to MSE.

Highlights

The maximum post exercise blood lactate concentration (BLCmax) has been positively correlated with maximal short-term exercise (MSE) performance
The aims of the present study were 1) to test whether the proposed bi-exponential 3-parameter model sufficiently describes the changes in BLC compared with the previously used 4-parameter model, and 2) to analyse how parameters are changed by the duration of the MSE
The reduction of the number of parameters decreased the goodness of the fit in every MSEs lasting 10 (MSE10) and in 3 tests under

Summary

Introduction

The maximum post exercise blood lactate concentration (BLCmax) has been positively correlated with maximal short-term exercise (MSE) performance. In the early 1980s, a bi-exponential 4-parameter model was developed to analyse the dynamics of lactate after exercise [9,10,11,12] It describes the post exercise BLC based on two compartments, the working muscle and the non-muscular lactate space, and assumes that the intra-vascular lactate concentration represents the average lactate concentration in the non-muscular space [11]. The two exponential terms describe the post exercise flux of lactate from the muscle into the non-muscular space and the subsequent disappearance of lactate out of the non-muscular space It includes the BLC at the end of exercise (BLCend_Ex), the amplitude (A1) and rate constant (y1) of the increase and the amplitude (A2) and the rate constant (y2) of the decrease of the BLC (Eq.1)

Objectives

Methods

Results

Discussion

Conclusion