ISSN:
1439-6327
Keywords:
Blood lactate
;
Anaerobic threshold
;
Previous supra-maximal exercise
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Twelve male and female subjects (eight trained, four untrained) exercised for 30 min on a treadmill at an intensity of maximal O2 consumption (% $$\dot V$$ O2max) 90.0%, SD 4.7 greater than the anaerobic threshold of 4 mmol ·1−1 (Than =83.6% $$\dot V$$ O2max, SD 8.9). Time-dependent changes in blood lactate concentration ([lab]) during exercise occurred in two phases: the oxygen uptake ( $$\dot V$$ O2) transient phase (from 0 to 4 min) and the $$\dot V$$ O2 steady-state phase (4–30 min). During the transient phase, [lab] increased markedly (l.30 mmol · l −1 · min −1, SD 0.13). During the steady-state phase, [lab] increased slightly (0.02 mmol · 1−1 · min−1, SD 0.06) and when individual values were considered, it was seen that there were no time-dependent increases in [lab] in half of the subjects. Following hyperlacticaemia (8.8 mmol -l−1, SD 2.0) induced by a previous 2 min of supramaximal exercise (120% $$\dot V$$ O2max), [lab] decreased during the $$\dot V$$ O2 transient (−0.118 mmol · 1−1 · min−1, SD 0.209) and steady-state (−0.088 mmol · 1−1 · min −1, SD 0.103) phases of 30 min exercise (91.4% $$\dot V$$ O2max, SD 4.8). In conclusion, it was not possible from the Than to determine the maximal [lab] steady state for each subject. In addition, lactate accumulated during previous supramaximal exercise was eliminated during the $$\dot V$$ O2 transient phase of exercise performed at an intensity above the Than. This effect is probably largely explained by the reduction in oxygen deficit during the transient phase. Under these conditions, the time-course of changes in [lab] during the $$\dot V$$ O2 steady state was also affected.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00357604
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