Lack of concordance amongst measurements of individual anaerobic threshold and maximal lactate steady state on a cycle ergometer

Abstract

Introduction: The calculation of exertion intensity, in which a change is produced in the metabolic processes which provide the energy to maintain physical work, has been defined as the anaerobic threshold (AT). The direct calculation of maximal lactate steady state (MLSS) would require exertion intensities over a long period of time and with sufficient rest periods which would prove significantly difficult for daily practice. Many protocols have been used for the indirect calculation of MLSS. Objectives: The aim of this study is to determine if the results of measurements with 12 different AT calculation methods and calculation software [Keul, Simon, Stegmann, Bunc, Dickhuth (TKM and WLa), D_max, Freiburg, Geiger-Hille, Log-Log, Lactate Minimum] can be used interchangeably, including the method of the fixed threshold of Mader/OBLA’s 4 mmol/l and then to compare them with the direct measurement of MLSS. Methods: There were two parts to this research. Phase 1: results from 162 exertion tests chosen at random from the 1560 tests. Phase 2: sixteen athletes (n = 16) carried out different tests on five consecutive days. Results: There was very high concordance among all the methods [intraclass correlation coefficient (ICC) > 0.90], except Log-Log in relation to the Stegamnn, D_max, Dickhuth-WLa and Geiger-Hille. The Dickhuth-TKM showed a high tendency towards concordance, with D_max (2.2 W) and Dickhuth-WLa (0.1 W). The Dickhuth-TKM method presented a high tendency to concordance with Dickhuth-WLa (0.5 W), Freiburg (7.4 W), MLSS (2.0 W), Bunc (8.9 W), D_max (0.1 W). The calculation of MLSS power showed a high tendency to concordance, with Dickhuth-TKM (2 W), D_max (2.1 W), Dickhuth-WLa (1.5 W). Conclusion: The fixed threshold of 4 mmol/l or OBLA produces slightly different and higher results than those obtained with all the methods analyzed, including MLSS, meaning an overestimation of power in the individual anaerobic threshold. The Dickhuth-TKM, D_max and Dickhuth-WLa methods defined a high concordance on a cycle ergometer. Dickhuth-TKM, D_max, Dickhuth-WLa described a high concordance with the power calculated to know the MLSS.

Keywords:

• IAT
• MLSS
• OBLA
• Lactate
• Cycle ergometer

Acknowledgments

Our team would like to thank the sportspeople who took part in the study, together with the collaboration of the TKM staff. This study would not have been possible without the collaboration of the Department of Physical Education and Sport of the University of the Basque Country (EHU-UPV).