Inclusion Criteria:  to be aged between 65 and 75 years old not involved in regular physical activities for at least 6 months (i.e., doing no physical exercise over twice per week); free of injuries as well as cardiovascular and respiratory disorders or central nervous system disease or receiving β-blocker medication; not using dietary supplements, smoking or drugs which interfere with the measurements; not using creatine supplementation, anabolic steroids, drugs, or medication with potential effects on physical performance; to have body index mass between 20 and 30 kg/m²; not to live above 800m of altitude; to be vaccinated against COVID-19 and to have no symptoms (fever, cough, fatigue, loss of smell or taste); able to complete all sessions; able to give consent.