Clinical Research Directory

Inclusion Criteria: * Age between ≥18 and 35 years in young adults and ≥ 55 and 80 years in older adults. * Body mass index (BMI) lower than 25 kg/m². * Physically active subjects (≥150 min/week of moderate exercise). * Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from performing physical exercise. * Participants capable of performing the tests. Exclusion Criteria: * History of neuromuscular, cardiac, or diseases that could affect liver or muscle metabolism. * Use of drugs or other stimulants that interfere with caffeine intake and intestinal absorption during the tests and study. * Body mass index (BMI) ≥ 25 kg/m². * Having undergone prolonged periods of forced physical inactivity during the 6 months prior to the study. * Performing strenuous exercise within 48 hours prior to the tests.• Failing to replicate the same food intake on the two experimental days. * Consuming caffeine after 6 PM on the day prior to training or testing.