Effects of methodological variations on lactate minimum identification

Abstract

The aim of this study was to analyze the influence of increment pattern as well as the stage duration on lactate minimum (LM) determination. Volunteers were eight physical active males [22.4 + 1.9 years; 177 ± 4.2 cm; 73.6 ± 5.4 kg; 23,4 ± 1,3 kg.(m2)-1] that performed, on different days, two incremental tests on cycle ergometer after lactic acidosis induction through 30 seconds Wingate test. Test 1- initial load of 1.75 kp and increments of 0.25 kp at each stage of 3 min until volitional exhaustion to determine the intensity corresponding to LM (LM1); Test 2- the intensities were 0.5 kp below, 0.5 kp above and the intensity at LM1 (at), the test 2 was composed by two parts (2a - stages of 3 min and 2b - stages of 6 min). The lactate concentration ([lac]), heart rate (HR) and exercise intensities corresponding to LM observed during parts 2a (LM2a) and 2b (LM2b) were compared to LM1. Differences were observed between the [lac] corresponding to LM1 and LM2a (4.9 ± 2.4 vs 6.2 ± 1.9 mM), as well as between the HR corresponding to LM2b (167 ± 14 bpm) and the HR corresponding to LM1 (159 ± 17 bpm) and LM2a (158 ± 12 bpm) (p < 0.05). However, no differences were observed for the intensities corresponding to LM1, LM2a and LM2b (2.6 ± 0.3 vs 2.6 ± 0.5 vs 2.6 ± 0.3 kp, respectively). We concluded that the methodological variations applied on present study did not interfere on the exercise intensity corresponding to LM.