Urban youth in Addis Ababa, Ethiopia face limited opportunities for physical activity due to urbanization and lack of recreational facilities. A quasi-experimental design was employed, with schools randomly assigned to intervention or control groups. Fitness test scores were measured at baseline and follow-up using standardised tests. The intervention group showed a statistically significant improvement in fitness test scores (mean increase of 15% in VO2 max) compared to the control group, although the effect size was modest. School-based physical activity programmes can positively influence urban youth fitness levels, but further research is needed to confirm long-term efficacy and optimal intervention parameters. Sustainable funding sources for continued programme implementation should be identified, alongside community engagement strategies to promote regular participation in physical activities. Urban Youth, Physical Activity, Fitness Test Scores, Addis Ababa, Ethiopia Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.