Abstract

Sixteen overweight men were submitted to 3 months of moderate-intensity training connected with respiratory muscle training: deep breathing (DB) and breathing through a tube (BT). All subjects underwent 2 identical control tests (C1 and C2), at the treadmill speeds 4, 5 and 6 km·h-1. During the test heart rate (HR), oxygen uptake (VO2), respiratory exchange ratio (RER), breathing frequency (Bf), tidal volume (TV), and minute ventilation (VE) were measured, as well as forced vital capacity (FVC), maximal voluntary ventilation (MVV), peak inspiratiory pressure (INSPp), peak expiratory pressure (EXPp), holding pressure during inspiration (HPinsp) and holding pressure during expiration (HPiexp.) The same protocol was repeated after the training (T). The HR and VO2 were no changed by training, RER was lower in DB (0.82 ± 0.01) than in BT (0.92 ± 0.01, p < 0.01). The Bf decreased and TV increased after training only in DB. The VE became elevated gradually with the increased treadmill speed in both groups of subjects. After training MVV was similar in DB and BT subjects, FVC was significantly increased in DB group (p < 0.04), INSPp increased significantly in both DB and BT (p < 0.03 and p < 0.01, respectively), whereas EXPp did not change. The Hpinsp increased only in BT p < 0.01, and Hpexp only in DB (p < 0.04). The present study showed that in moderately obese men deep breathing training changes favorably the pulmonary function. The exercise-induced decrease of RER after DB training suggests increased contribution of fat oxidation to total energy expenditure. Verf.-Referat