The functional parameters at the level of the "anaerobic threshold" (ANT) are used very frequently to characterize aerobic functions of the organism. For estimation of the ANT most frequently changes of the LA blood concentration in relation to an increasing load are used. The LA concentration depends to a considerable extent on the state of glycogen reserves in muscles which may change as a result of physical loads and as a result of dietary intervention. Ventilation parameters and values of the GR are practically independent on glycogen reserves. For the evaluation of mutual relationships between parameters at the level of the ventilation ANT and the level of ANT assessed by means of changes of the HR, both ANT values were assessed in a group of trained endurance runners on a treadmill and in a group of untrained young men on a bicycle ergometer. For practical use both ANT estimations can be considered identical, assuming that when using the HR for assessment of ANT we implement the following conditions: 1. The initial intensity of the load is at the level of 50 VO2max. or lower. 2. The duration of different grades of the load is 30-150 s. 3. Differences in the intensity of the load between different grades are 4-6 strokes. 4. The total number of loads varies between 7 and 12.(ABSTRACT TRUNCATED AT 250 WORDS)