Effects of HIIT and MICT Training on Cardiorespiratory Fitness, Testosterone/Cortisol Ratio, and Mental Health in Young Adults

Inclusion criteria: * Men and women aged 18 to 21. * Lead a sedentary or moderately active lifestyle (IPAQ ≤600 METs-min/week). * Subjects diagnosed by a physician as fit for physical exercise. * Informed consent form signed by the study subjects. Exclusion criteria: * Subjects with any motor disability. * Pregnant women. * Subjects with metabolic disorders. * Subjects with chronic respiratory diseases such as asthma, emphysema, or cancer, obstructive pulmonary disease. * Subjects with high blood pressure or arrhythmia. * Failure to sign the informed consent form. * Subjects who are in a high-performance physical training program. * Women with irregular menstrual cycles who take contraceptive medication to regulate their menstrual cycle. * Consumption of caffeine, alcohol, and tobacco or use of electronic cigarettes. * Subjects with a cyclical diagnosis of anxiety and depression by a specialist. * Frequent consumption of alcoholic beverages (more than 7 drinks per week for women and more than 14 drinks per week for men) or a history of excessive alcohol consumption. * Subjects who consume dietary supplements (caffeine, nitric oxide precursors, beta-alanine, creatine, sodium bicarbonate, or L-carnitine). Elimination criteria: * Voluntary withdrawal from the study. * Attendance at less than 80% of intervention sessions. * Incomplete measurement schedule or insufficient sample size. * Joint or muscle injuries caused by the training program. * Overtraining syndrome.