Purpose. The aim of this study was to derive the regression equation for predicting VO2max of athletes by the relatively new submaximal 3'Bike Test. Methods. This test was conducted on 1501 active football male players, aged 16÷35 years. A medical anamnesis was administered and then the athletes’ weight was measured. Afterwards, the athletes performed the 3'Bike Test followed by the Astrand Bike Test for comparison reasons. Results. Linear regression of the data indicated that the produced regression model, as a whole, is statistically significant. In addition, the system of predictive variables was able to explain for 48% of total variability of the criterion variable VO2maxAST. According to the regression coefficients that had been derived, a regression equation that could predict VO2max was created. A significant high correlation (r = 0.688) and a non-significant paired t-test (p = 0.782) found between the measured VO2max (Astrand test) and the predicted VO2max (3'Bike Test) indicates a large similarity between the predicted and measured VO2max values. Conclusions. The 3'Bike Test was found to be a capable measurement tool of aerobic endurance, more reliable and valid than the Astrand submaximal test, as well as being shorter, more easily executed and a better predictor of VO2max.