Abstract

Two series of investigations were carried out on 13 runners. In the first series, performed on an inclined treadmill and aimed at determination of VO2 max, workload was gradually increased every minute. The second series included four 4 min exercises. Physiological and biochemical parameters at the anaerobic threshold level were analyzed. The individual values of respiratory parameters (VE, VO2, VCO2, FEO2, FECO2 and RQ) determined in the first and second series, and of biochemical parameters (LA, BE, H+) in the second series, were presented as the system of coordinates in the function of running speed. Three different criteria of anaerobic threshold (AT) level determination were applied: 1) non-linear increase of pulmonary ventilation and CO2 production, and FEO2 increase without parallel FECO2 changes, 2) marked increase of blood lactate concentration, and 3) lactate concentration equal to 4 mmol/1. The first criterion was applied in both series. The results revealed that AT level determined in 4 min exercises using the first and second criteria was similar. On the other hand, despite the same criterion, the threshold level of almost all physiological parameters was higher in the first, as compared with that in the second series. However, as regards exercise intensity and oxygen uptake at AT, the differences between the two methods were slight when the values were related to the maximum values in the particular series. The basic advantage of the first method is a shorter duration of the whole test and a possibility to determine the actual maximum oxygen uptake, while its limitation is the HRAT, non-convergent with the other methods of HRAT determination. Verf.-Referat