Aerobic fitness seems to be important for soccer players. Some studies have shown a relationship between aerobic capacity and ranking, team level and distance covered during the match (Smaros, 1980; Apor, 1988; Wisløff et al., 1998). Recenlly, Helgerud et al. (2001) have also shown that aerobic training can improve some soccer performance characteristics such as distance covered during a match, high intensity phases, number of sprints and involvements with the ball. For these reasons, training programmes commonly include acrobic conditioning. To control the effectiveness of training stimuli in improving aerobic capacity, several classical laboratory tests ( test with determination of ventilatory or lactate anaerobic thresholds) and/or field measures like shuttle run tests (Yo-Yo test, Leger test, etc.) can be used. However, all these assessments require maximal effort and, consequently, motivation can strongly influence tests results and they are sometimes not well accepted by soccer players especially during the season or close to important matches.