Abstract
This study aims to investigate the effect of traditional sports in order to improve physical fitness of young athletes. Researchers adopted an 11-week randomized controlled trial design. Participants included young athletes from Sultan Ageng Tirtayasa University (Indonesia) who were allocated to TSG (n = 20) and CG (n = 20). Analysis of Students’ t-tests for paired samples used to test differences in physical fitness among males and females in two groups at the pre-test and post-test stages. The effect size test (Cohen’s d) was used in this research. The first findings showed that male participants in TSG had differences in physical fitness in the pre-test and post-test stages related to Multi-stage (p <  0.001, d = −2.17), Shuttle run: 4×10 meters (p <  0.001, d = 2.43), 30 meter run test (p <  0.001, d = 1.85) and sit and reach test (p = 0.002, d = −1.41), while male participants in CG had differences in physical fitness in terms of Shuttle run: 4 ×10 meters (p <  0.001, d = 1.69), Run test 30 meters (p <  0.001, d = 1.64), but no differences were found for other components. The second finding showed that female participants in TSG had differences in physical fitness in the pre-test and post-test stages related to Multi-stage (p <  0.001, d = −1.53), Shuttle run: 4×10 meters (p <  0.001, d = 2.76), 30 meter Run test (p <  0.001, d = 2.02) and Sit and reach test (p < 0 .001, d = −1.72), while the female participants in CG had differences in physical fitness in the 30 meter Run test (p <  0.001, d = 2.87), but no differences were found for the other components. In conclusion, this research proves that traditional sport for 11 weeks can improve the physical fitness of young athletes.

Keywords
traditional sport, physical fitness, young athletes