The purpose of this study is to assess the effect of post-operative inspiratory muscle training on muscle strength and endurance in patients with obesity submitted to gastroplasty.

Gastroplasties, like other major abdominal surgeries, induce mechanical changes in the lungs and decreases of the respiratory muscle strength in the post-operative periods. Depending on the occurrence of pre-existing disturbs, obese patients may exhibit severe declines of respiratory function after these surgeries.

Post-operative respiratory physiotherapy is a valuable intervention, involving a set of techniques aimed to expand pulmonary volumes and to improve arterial oxygenation, leading to decreases on the development of atelectasis and pneumonias. It induces faster recovery of respiratory function and reduction of lung complications, what may be particularly important in high-risk patients like over-weighted subjects.

There are scanty data about the role of respiratory muscle training in the post-operative period. This is particularly true regarding inspiratory muscle training of obese patients submitted to gastroplasties.

Inclusion Criteria:

• gastroplasty patients presenting body mass index (BMI) ≥ 35 kg/m2;
• weighting ≤ 60 kg/m2;
• capable of fulfilling the experimental protocol.

Exclusion Criteria:

• acute or chronic pulmonary disease;
• smoking;
• post-operative mechanical ventilation for more than 48 hours;
• presence of lung complications;
• need for surgical re-intervention during the study period.