Inclusion Criteria:  aged ≥ 18 and ≤ 50 years. men experienced, well-trained endurance runners with the capacity to run 21km in less than 1h 40 and who train more than 5h a week. free from muscular, bone or joint injuries free from neurologic disease approval received from a physician  Exclusion Criteria:  currently participating in a structured exercise program injury in the 3 months prior to the protocol chronic joint pathologies (e.g.: repetitive sprains, patellar or ligament problems) the intake of corticosteroids within 3 months (inhalation, infiltration or history of prolonged corticosteroid therapy).