The study was conducted to assess the impact ofadditional days aerobic and anaerobic training on u17 male youth football project in Mertulemariam town. In the study area, foot ball coaches usually prefer to deliver trainings ofthree days in a weekfor any age levels; but the researcher believes that such training does not provide youth players with better agility, speed., strength and endurance. The samples were selected using purposive sampling techniques. Thus, a total of32 football players were participated and jield-based tests to assess physical jitness ofendurance, strength, speed, and agility were principally employed. Mean, SD and independent sample tests were conducted to assess the performance offootball players' physical jitness. The result ofthis study indicated that there was better significance mean difference between the pre and post tests regarding to the impact of additional days aerobic and anaerobic training on the physical quality development on the u-17 male youth football project in Mertulemariam. The study indicated that there existed a significant endurance, strength, agility and speed performance levels between those with three days a week training and those with jive days training. It has been observed in the analysis that players who exercised for jive days a week were better ofin physical jitness capacity compared to those who exercised only jor three days a week. For example the post-test endurance performance levels of the groups showed a statistically significant difference (t=3.37, df=30,p=0.002) indicating that the group members who had jive days a week endurance training significantly outperformed better than the group members who had three days a week training. In addition the mean score of G-1 was 2357.1 and G-2 was 2706.2. It indicates there is a huge gap between these two groups. The me,an difference was 349.1 implying that jive days a week training has greater endurance performance. The researcher found that it was better to enhance the physical jitness ofplayers (f additional two days (a total ofjive days) oftraining is made available for them than providing them with only three days oftrainings.