The aims of this study were to use the Maximal Aerobic Speed (MAS) to set training intensities for aerobic training and to measure the effects of two different training programmes on MAS and on the running time to exhaustion at 100% of MAS (Tlim) for 121 students aged 14 to 17 years. The MAS was measured using the Université de Montréal Track Test (UMTT). This measurement was found reproducible for males (r = 0.93) and females (r = 0.68). The Students followed a 12-week training programme of one weekly training session. The MAS and the Tlim were measured the weeks before and after training. Two training programmes were proposed (intense training programme and moderate training programme). These training programmes differed by the ratio between continuous exercises (85% of MAS) and intermittent exercise (between 90% and 120% of MAS). For the moderate training programme, the ratio between continuous and intermittent exercises was greater than for the intensive training programme. Twenty subjects served as control group. The students MAS and Tlim (mean +/- SD) were respectively 13.7 +/- 1.6 km.h-1 and 380.5 +/- 91.8 s for the males and 11.3 +/- 1.2 km.h-1 and 347.2 +/- 91.1 s for the females. Our results indicated that only the subjects of the intense training group improved their MAS: + 5.7% for the males (p < 0.001) and + 5.4% for the females (p < 0.001). In neither case was Tlim significantly improved with training. In conclusion, we can notice that MAS is a pertinent criterion to set training intensities for aerobic training and that a weekly training session over 12 weeks is sufficient to moderately improve the MAS of initially untrained students.