High-Intensity Interval Training Effects on Fitness in Youth Soccer Players

This study aims to investigate the effects of an 8-week high-intensity interval training (HIIT) program on aerobic capacity, anaerobic power, blood lactate levels, and sprint performance in young male soccer players. Twenty-four volunteer U19-category soccer players from Sivasspor A.Ş. were randomly allocated into an experimental group (n=12), which performed HIIT three days per week for 8 weeks in addition to their regular training, and a control group (n=12), which continued only their routine training program. Anthropometric measurements, resting heart rate, aerobic performance (Yo-Yo IRT1), anaerobic performance (RAST), and blood lactate levels were assessed before and after the intervention period.

Inclusion Criteria: * Active male soccer player registered in the U19 category at Sivasspor A.Ş. Football Club * Regularly participating in team training sessions prior to the study * Voluntary participation with written informed consent obtained from parents or legal guardians * Free from any injury or health condition preventing participation in high-intensity exercise Exclusion Criteria: * Presence of a musculoskeletal injury within the past 3 months * Diagnosis of any cardiovascular, metabolic, or chronic health condition * Attendance rate below 90% during the 8-week training program * Withdrawal of consent by participant or parent/legal guardian