Dynamic ventilatory responses to submaximal exercise in obese adults

Background: Obesity increases mechanical stress on the respiratory system, leading to changes in breathing mechanics during physical activity. Aim: The aim of the study was to examine the dynamic ventilatory responses elicited by a submaximal exercise test in obese adults and to compare these responses with those of their non-obese peers. Methods: Twenty-nine obese individuals (32±4/years) without chronic respiratory diseases and 30 non-obese peers (29±3/years) were included in the study. Exercise capacity and dynamic ventilatory responses were assessed using Spiropalm®-equipped six-minute walk test (6MWT). Inspiratory capacity (IC), minute ventilation (VE), and respiratory frequency (RF) were evaluated at rest and post-test. VEpeak and peak breathing reserve (BRpeak) were recorded. Results: The six-minute walking distance of obese participants (479.21±47.16 m) was significantly lower than that of their healthy peers (584.61± 48.42 m) (p<0.001). While there was a significant difference between the groups in the change of VE at baseline and post-6MWT (p=0.017), changes in IC and RF were similar (p>0.05). BRpeak was lower in obese adults (p<0.001), whereas VEpeak was found to be higher in this group (p<0.001). Conclusion: This study shows that obese adults exhibit altered ventilatory responses to submaximal exercise compared to their non-obese peers. Even in the absence of chronic respiratory diseases, these results indicate an increased ventilatory demand which may contribute to exercise intolerance and increased respiratory effort in obesity. These ventilatory adaptations could help inform targeted interventions aimed at improving exercise tolerance and respiratory capacity in this population.