Ashira Hiruntrakul, Parichat Rirermkul, Tanapol Kaewwong, Surumpa Charoensuk Kaewwong, Austtasit Chainarong, Nur Azis Rohmansyah, Charee Jansupom
Background and Study Aim. Core muscles are a key part of any swimmer's training, and using a high-intensity interval training approach can help support an athlete's performance. The aim of this study was to evaluate the effectiveness of a six-week core muscle high-intensity interval training (CM-HIIT) regimen on VO₂max, vital capacity, and body composition in male swimmers. Material and Methods. Twenty male swimmers with similar 50-meter swimming performances participated in the study. They were randomly assigned to two groups. The experimental group (n = 10; age = 21.4 ± 0.84 years, BMI = 25.19 ± 5.00 kg/m²) performed CM-HIIT three days per week. The control group (n = 10; age = 20.4 ± 0.70 years, BMI = 24.99 ± 6.42 kg/m²) followed their usual swimming training program. VO₂max was assessed using the YMCA submaximal cycle test, vital capacity was measured with a spirometer, and body composition was evaluated using bioelectrical impedance analysis. Results. After six weeks, VO₂max significantly increased compared to baseline (p < 0.05). Vital capacity also showed a significant improvement, with higher values observed after six weeks (p < 0.05). Body composition improved, with significant reductions in body fat percentage and fat mass, while muscle mass increased in the experimental group (p < 0.05). Additionally, Max HR significantly decreased after four and six weeks, whereas resting HR showed no significant changes. In the control group, body fat percentage and fat mass significantly decreased, but no significant differences were observed in body weight, BMI, or muscle mass. Conclusions. Core muscle high-intensity interval training induces physiological adaptations, enhances cardiovascular fitness, and improves body composition in trained swimmers, all of which are critical for swimming performance. However, coaches and trainers must carefully monitor training intensity to optimize oxygen uptake while ensuring safety and performance efficiency. © Ashira Hiruntrakul, Parichat Rirermkul, Tanapol Kaewwong, Surumpa Charoensuk Kaewwong, Austtasit Chainarong, Nur Azis Rohmansyah, Charee Jansupom, 2025.
Sports and Exercise Science Program, Faculty of Interdisciplinary Studies, Khon Kaen University, Thailand; Sports Science Research and Development Division, Sports Science Department Sport, Authority of Thailand, Thailand; Sport Science Program, Faculty of Liberal Arts and Science, Roi Et Rajabhat University, Thailand; Faculty of Sport Science, Burapha University, Thailand; Department of Elementary School Physical Education, Universitas Negeri Yogyakarta, Indonesia; Sport and Health Science Program, Faculty of Science and Liberal Arts, Rajamangala University of Technology Isan, Thailand
