We performed a comparative study to analyse the importance of intermittent training, more precisely the use of intermittent\u00a0maximal aerobic speed (MAS), in football. We assessed continuous MAS with the MAS-EVAL test and intermittent MAS with\u00a0the 45-15 test using 21 young footballers. Bearing in mind the results two uniform groups were formed who did seven weeks\u00a0of specific training in order to develop their MAP. Training intensity was indexed to the maximum level of continuous MAS\u00a0for group 1 and to maximum intermittent MAS for group 2. For all the players and for each group there was a significant\u00a0initial difference (p<\/em> <0.001) between intermittent MAS (16.02\u00b11.21 kph) and continuous MAS (14.12\u00b11.06 kph). The same\u00a0differences between intermittent and continuous MAS were maintained once the 7 weeks of training had finished. However,\u00a0for group 1 there were no significant differences between the initial and final 45-15 tests, in contrast to group 2 where there\u00a0was a clear difference (p<\/em> <0.01) between the two intermittent tests (15.86\u00b11.50 kph \/ 17.0\u00b10.97 kph). Although both\u00a0groups improved their continuous MAS the speed increase was higher in group 2. It is very important to consider the results\u00a0of continuous and especially intermittent MAS tests to schedule and accurately tailor the intensity of training, since there are\u00a0differences that are not always assessed.<\/p>\n\n