The study was designed to test the following hypotheses: In obese patients with OSAS, the benefit of the combination of exercise training + continuous positive airway pressure (CPAP) will be higher than CPAP alone in term of functional capacity, metabolic, inflammatory, cardiovascular and sleep parameters and quality of life. In obese patients with OSAS, the benefit of training using ventilatory assistance (NIV) during cycloergometer \[cycloergometer with NIV\] or respiratory muscles training (spirotiger) in addition to cycloergometer \[cycloergometer + spirotiger\] will be higher than cycloergometer training alone \[cycloergometer\] in term of functional and exercise capacities. Dyspnea during walking test and respiratory muscle strength at baseline could influence the response to combined exercise training such as \[cycloergometer + NIV\] or \[cycloergometer + spirotiger\]