Inclusion Criteria:  60 to 80 years of age; Being physically inactive (less than 150 min/week of moderate to intense physical activity); No chronic cardiovascular, respiratory, metabolic or neuromuscular disease counterindicating an exercise training or hypoxic conditioning program; Health coverage; Being able to provide written fully informed consent.  Exclusion Criteria:  Body-mass index >30 kg/m2; Smoking (> cigarettes/day); Alcohol use (> 10g/day); Mental disorder or history of mental disorder; Beta-blockade treatment; Inability or refusal to provide informed consent; No health coverage People exceeding the annual ceiling of allowances received as a result of their participation in other clinical trials; People deprived of freedom by judicial or administrative decision; People subject to legal protection, who cannot be included in clinical trials.