HIIT, Cardiorespiratory Fitness, and Metabolic Health in Healthy Young Adults

The purpose of this study was to investigate the effects of a high-intensity interval training (HIIT) intervention on cardiorespiratory fitness (CRF) and cardiometabolic health in active male university students. The main question it aims to answer is: Does HIIT improves CRF and cardiometabolic outcomes, including blood pressure, lipid profile, and insulin resistance estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Researchers will compare HIIT (designed to experimental group) to non-training intervention (designed to control group) to see if the training program works to improve the cardiometabolic health status. The HIIT program consisted of three sessions per week for 9 weeks, comprising of three sets of six to eight 30-second running bouts performed at 100-110% of maximal aerobic speed (MAS), interspersed with 30-second active recovery runs at 50% MAS between bouts.

Inclusion Criteria: * Male university students at the High Institute of Sport and Physical Education, Kef, Tunisia. * Aged 19 to 25 years * Provided written informed consent Exclusion Criteria: * Acute or chronic disease contraindicating vigorous physical exercise * Musculoskeletal injury or any other medical condition limiting participation in exercise * Participation in another structured training program within the previous 6 months * Current or recent (within the previous 3 months) use of medications or dietary supplements that could influence the study outcomes