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

Overview

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.

This experimental study was designed to examine the effects of an 8-week HIIT protocol, applied three days per week, on selected physical performance parameters in youth soccer players. Participants were randomly divided into an experimental group and a control group. Height was measured using a Harpenden stadiometer and body weight using a digital scale. Aerobic performance was assessed using the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IRT1), with heart rate monitored via a Polar Team Pro 2 device. Anaerobic performance was evaluated using the Running-based Anaerobic Sprint Test (RAST). Blood lactate concentration was measured using a portable lactate analyzer from finger-tip capillary blood samples at rest and following the RAST protocol. All measurements were taken as pre-test and post-test assessments, before and after the 8-week intervention period. The study was approved by the local Clinical Research Ethics Committee (2021/243) and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from the parents/legal guardians of all participants prior to testing.