VERY SHORT-TERM HIGH-INTENSITY INTERVAL TRAINING IN HIGH SCHOOL SOCCER PLAYERS
Kun Ho Lee, Kyu-Jin Lee, Yong Chul Choi
Abstract
Background and objective To analyze the body composition, anaerobic power, and fatigue in high school soccer players resulting from very short-term, high-intensity interval training (HIIT) for 3 weeks during off season. Methods Forty-four high school soccer players, with a mean age of 17.2 ± 1.0 years, were included in the study. The sample consisted of a single group, and the tests measured body composition using the impedance method, anaerobic power using a Wingate cycle ergometer, and strength with an isokinetic device. The training was carried out 5 days/week over a 3-week period for a total of 15 sessions. Training included stretching and warming up, sprint anaerobic cycle training, and running HIIT such as sidestep, zigzag run, ladder run, box jump, and plyometrics. Results Post-training muscle mass (+2.0%, p < 0.001) and fat ratio (−12.7%, p < 0.001) improved significantly compared to pre-training observations. However, bodyweight and body mass index (BMI) did not change significantly. The Wingate test, measuring peak power in three and five sets showed greater improvement compared to the initial test (+10.7% and +19.0% respectively). A significant decrease was observed for fatigue in three and five sets (−8.5% and −12.4% respectively). The isokinetic strength test showed significant differences in flexion(+8.5%, p = 0.002) and extension (+9.4%, p < 0.001) at 60°/s. Conclusion Short-term HIIT can improve fatigue rate, anaerobic power, and muscle strength of athletes as well as increase their muscle mass.