Inclusion Criteria:  Group 1: high-level athletes (qualified for national/international championships and/or training at least 15 hours/week) Group 2: recreational athletes who practice a regular physical activity  Exclusion Criteria:  Participation in another trial History of cardiac pathology High blood pressure History of ulcers and other gastrointestinal disorders Myasthenia Renal insufficiency Person not affiliated or not benefiting from a social security system