Objective: The aim of this study was to compare eight weeks of continuous training with interval training on lean mass, fat mass, skeletal muscle index, anaerobic power, and oxygen consumption in adolescent amateur soccer players.

Research method: This study was a quasi-experimental type. The statistical population of this study was adolescent amateur soccer players in Shiraz. Sampling was done in a multi-stage with 24 people selected. The results were analyzed using SPSS26 software. The significance level is p<0.05.

Findings: Comparison of the mean variables in continuous training showed that there was no significant difference in lean mass, skeletal muscle index, and anaerobic power; but there was a significant difference in fat mass and oxygen consumption. Comparison of the mean variables in interval training showed that there was a significant difference in lean mass, fat mass, skeletal muscle index, anaerobic power, and oxygen consumption. Post-test comparison between training groups showed that there was no significant difference in lean mass, fat mass, skeletal muscle index, and oxygen consumption between training groups, but there was a significant difference in anaerobic power.

Discussion and Conclusion: The findings of this study showed that continuous training had no significant effect on lean mass, mean skeletal muscle index, and anaerobic power; but it significantly increased cardiorespiratory endurance capacity and decreased fat mass. Also, interval training had a positive effect on lean mass, skeletal muscle index, fat mass, anaerobic power, and cardiorespiratory endurance. Comparison between training groups showed that only mean anaerobic power had a significant difference.