Obesity seems to be related to reductions in the inspiratory muscle strength. However, the effects of obesity on inspiratory muscle resistance have not been studied yet. The objective of this study was to compare the inspiratory muscle resistance between obese and eutrophic individuals.

Participated 20 obese (31±6 years old, 10 men, 37.5±4.7kg/m²) and 20 healthy subjects (29±8 years old, 10 men, 23.2±1.5kg/m²). Inspiratory muscle strength was measured by a manovacuometry through the determination of the maximum inspiratory pressure (MIP). Inspiratory muscle endurance was determined by an incremental test with an initial load of 50% MIP and increments of 10% MIP every 3minutes until the individual was unable to continue the test.

Obese (470±326 s) showed a reduction in inspiratory muscle resistance compared to eutrophic individuals (651±215 s, P=0.04). Inspiratory muscle strength did not differ between groups (Obese=120±45 cmH₂O; Eutrophic=118±31cmH₂O, P=0.81). Inspiratory muscle endurance test induced a similar increase in systolic, diastolic and mean arterial pressure, as well as in heart rate in obese and eutrophic individuals (Table 1).

Obeses show reduction in inspiratory muscle resistance compared to eutrophic individuals, but the hemodynamic responses did not differ between groups.