Mirza Asmara, Yudik Prasetyo, Bernadeta Suhartini, Gallant Pamungkas, Burhan Shodiq
Background. Adolescence is characterized by heightened trainability, yet approximately 18 % of young people are overweight or obese. It has been noted that in five Yogyakarta futsal clubs, 37–51 % of U17 players show BMI ≥ 25 kg·m-2, potentially hampering performance. Objectives. This study aimed to examine whether implementing an eight-week resistance-training programme enhances 20-m sprint speed, lower-body strength, and explosive power in U17 futsal athletes, and whether body fat change mediates these effects. Materials and methods. Thirty 18-19-year-old male players completed periodised resistance sessions that were conducted on a thrice-weekly basis. Body mass, BMI, body fat percentage (BF %), sprint time, one-repetition-maximum leg press, and standing long-jump distance were measured in the pre-/post-intervention phase. Paired-sample t-tests were used to assess within-group changes. Mediation models (PROCESS; 5,000 bootstraps) examined whether ΔBF % transmitted the influence of ΔBMI on performance. Results. A substantial decrease was observed in body mass (–1.21 kg), BMI (–0.43 kg·m-2), and BF % (–1.48 %), while sprint time (–0.95 s), leg-press strength (+11.9 kg), and jump distance (+11.8 cm) improved (all p < .001). ΔBMI predicted ΔBF % (B = 5.38, p < .001). BF % partially mediated the BMI–sprint link (indirect effect = 3.52, 95 % CI [2.70, 4.47]), although a significant direct path persisted. Mediation was non-significant for strength and power; BMI reduction showed no relation to strength change, yet retained a strong direct association with power gains independent of BF %. Conclusions. The findings of this study indicate that resistance training markedly improves neuromuscular performance and body composition in youth futsal athletes. A lower BMI enhances sprint speed both directly and through concurrent reductions in BF %, whereas adaptations in strength and power arise through mechanisms other than adiposity. Training programmes should therefore combine neuromuscular loading with strategies for healthy weight management to optimise youth futsal performance. © Asmara, M., Prasetyo, Y., Suhartini, B., Pamungkas, G., & Shodiq, B., 2025.
Department of Sport Science, Faculty of Health and Sport Science, Universitas Negeri Yogyakarta, Colombo St, 1, Sleman, Yogyakarta, 55281, Indonesia; Department of Sports Engineering, Faculty of Industrial Technology, Institut Teknologi Sumatera, Terusan Ryacudu St, Lampung Selatan, Lampung, 35365, Indonesia
