Heart rate at submaximal activity levels and decreases in heart rate during recovery are important criteria in the assessment of athletes' aerobic performance. In this study, the data of 19 female and 26 male physical education students who were tested on a bicycle ergometer according to a gradually increasing workload protocol followed by an active recovery period of 6 min are assessed. The following data are used: $VO_2$max (maximal aerobic power), $VO_2$ (volume of oxygen used per min during exercise) at the 4.0 mmol/l lactate level, the decreases in the heart rate (HR) (with respect to the maximal HR) in the third and sixth minutes during recovery. Our purpose was to determine the correlations between both $VO_2$max and $VO_2$ at the anaerobic threshold and the decreases in HR in the third and sixth minutes during recovery in the males or females and regardless of gender. Statistical analyses revealed the following results: significant correlation coefficients between $VO_2$ at the anaerobic threshold and the decrease in HR in the third and sixth minutes during recovery in males, females and in total; significant correlation coefficients between $VO_2$max and the decrease in HR in the third and sixth minutes during recovery in all subjects considered as a group, but not in males or females alone. However the correlations were not close to r - 1.00, therefore it would not be very precise to assess aerobic performance according to the extent of decrease in the recovery HR.