[Noninvasive determination of the anaerobic threshold in middle-age men]

The "anaerobic threshold" was estimated non-invasively in two groups of untrained middle-aged men (Mean age 31.4 +/- 4.8 and 51.8 +/- 5.4 years) simultaneously from minute volume dependence on oxygen consumption or CO2 output, and by means of pulse rate kinetics estimation, both at a growing intensity of exertion. The values of selected function variables (VO2, pulse rate and performance in pedalling) at "threshold" level showed no significant difference in either estimation in both absolute and relative quantities (expressed in per cent of maximum values). Very close relationships were found between the values of selected function parameters at "anaerobic threshold" level estimated with the above two methods (p less than 0.005 in all cases). The two methods of "anaerobic threshold" estimation are interchangeable under the following conditions: the initial intensity of exercise at about 50% VO2 max level, the duration of each degree of exertion ranges between 30 and 150 seconds, the differences in the intensity of exercise between different degrees are roughly 4 to 6 pulses/min, and the total number of the degrees of exercise is 5 to 8. Estimations of pulse rate kinetics with the intensity of exercise rising can be utilized for the determination of the "anaerobic threshold" even in persons of advanced age both under laboratory and under field conditions.