Effect of 40 Weeks of Endurance Training on the Anaerobic Threshold*

Abstract

The effect of a 40-week training program on the anaerobic threshold (AT) was studied in five subjects (35 ± 5 yrs). The training program consisted of a bicycle ergometer exercise 1 h per day 3 days a week at a work load corresponding to 80%-85% of V̇O₂max. Before training (S₀) and at the 10th, 20th, 30th, 40th weeks (S₁₀, S₂₀, S₃₀, S₄₀) of the training program, ventilatory AT (AT vent), lactate AT (AT lact), and 4 mmol AT were estimated using a graded exercise test. In the same period, another test (1) to determine V̇O₂ max, maximal work load (MWL), and net efficiency (2) and a 1-h endurance exercise requiring 85%-90% of V̇O₂ max were performed. After training, AT increased significantly by 10%, 11%, and 18% in AT vent, AT lact, and AT 4 mmol, respectively. MWL and net efficiency increased by 22% and 14% respectively, and there was no significant increase in V̇O₂ max. The AT increase at S₂₀ was delayed as compared to the change in MWL (S₁₀). It is hypothesized that an AT increase provides good evidence for modifications of the muscular oxidative capacities during an endurance training program. A part of this paper is devoted to (1) the study of the reproducibility of AT estimation, (2) a comparison to other methods for determining the definition of AT, and (3) the correlations between the three methods utilized for AT estimation.

endurance training - maximal oxygen uptake - maximal work load - net efficiency - anaerobic threshold - blood lactate