A Comparison of Methodologies in Detection of the Anaerobic Threshold

Dickstein, Kenneth MD
Barvik, Stale MD
Aarsland, Torbjorn RN
Snapinn, Steven PhD
Karlsson, Jan PhD

Cardiopulmonary Exercise Laboratory, Cardiology Department (K.D., S.B., T.A., S.S.), Central Hospital in Rogaland, Stavanger, Norway, and the Department of Clinical Physiology (J.K.), Karolinska Institute, Stockholm, Sweden.

Address for correspondence: Kenneth Dickstein, MD, Cardiovascular Division, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.

Circulation 81:p II-46, January 1990.

Peak cardiopulmonary exercise performance is readily evaluated. The most appropriate methodology for assessment of submaximal exercise performance, however, is a subject of controversy. Therefore, we assessed the difference between conventional methodologies using standard criteria to estimate the onset of anaerobiosis and compared them with known gas exchange and blood lactate ([La]) concentrations. Oxygen uptake (V̇o₂) was determined at both the gas exchange anaerobic threshold (ATge) and the lactate threshold (LaT) using the following three types of commonly used methodologies in a blinded fashion: 1) conventional techniques based on manual inspection of plots of gas exchange indexes and [La] versus time, 2) computerized linear regression analysis of two-segment model plots for V̇co₂ versus V̇o₂ and log [La] versus log V̇o₂, and 3) fixed values determining the V̇o₂ at a respiratory exchange ratio (V̇co₂/V̇o₂) of 1.00 and at an [La] of 2 mmol/l. Respiratory exchange data were collected on a breath-by-breath basis in 30 men with documented myocardial infarction. Simultaneously, arterial blood was sampled for [La] every 20 seconds during maximal exercise on an upright bicycle ergometer programmed for a continuous ramp protocol of 15 W/min. The mean (±SD) peak V̇o₂ was 1,463 (±312) ml/min. The mean (±SD) V̇o₂ values for each method were as follows: n=30 LaT ATge Method V̇o₂ (mi/min) % Peak V̇o₂ (mi/min) %Peak r 1 (±SD) 917 (±226) 62.6 928 (±161) 63.4 0.77 2 (±SD) 853 (±296) 58.3 941 (±202) 64.3 0.69 3 (±SD) 1,101 (±237) 75.3 1,123 (±255) 76.7 0.81 These results indicate that a good positive correlation exists between the gas exchange and lactate data by all three approaches. The chosen fixed values yield the highest threshold detection for both ATge and LaT. Detection was lowest using regression analysis for LaT. The difference between the fixed and manual methods for LaT was fairly constant at approximately 150–200 ml/min V̇o₂, whereas the difference was much more variable in all other cases. The most consistent relation was observed between the manual and regression methods for ATge determination. Our data demonstrate that the techniques commonly used for estimation of the anaerobic threshold are in good agreement with each other, although small systematic differences are observed. These differences should be taken into consideration when using these methods to evaluate submaximal exercise performance.