Breathlessness descriptors during constant load cycling in obese men with and without dyspnea on exertion

Abstract

During constant load exercise, some otherwise healthy obese men experience dyspnea on exertion (+DOE), while others do not (−DOE). Their subjective respiratory sensations may explain why the intensity of breathlessness is greater in +DOE.18 obese men participated and were divided based on their Ratings of Perceived Breathlessness (RPB, Borg 0–10 scale) during minute 6 of constant load (90 W) cycle exercise; ten +DOE (RPB ≥ 4) (36 yr, 39 BMI, 3.1 L/min peak V̇ O2, 104% predV̇O2) and eight −DOE (RPB ≤ 2) (34 yr, 35 BMI, 3.0 L/min peak V̇O2, 104% predV̇ O2). After the exercise, subjects filled out a questionnaire asking them to pick three of fifteen descriptors that best described the respiratory sensations they felt. Data were analyzed using z‐test proportion comparisons and clusters.Both +DOE and −DOE groups chose descriptors with similar frequency, only “I feel that I am breathing more” (+DOE 80%, −DOE 50%) and “I feel that my breathing is rapid” (+DOE 20%, −DOE 50%) differed slightly but not significantly between the groups (p=0.37). The top four clusters were ‘Breathing more’ (67% of all participants), ‘Heavy’ (44%), ‘Work/Effort’ (44%), and ‘Rapid” (33%).We conclude that obese men with and without DOE describe their respiratory sensations similarly during submaximal exercise, although their intensity of breathlessness is different.Supported by HL096782, King Charitable Foundation Trust, ALA, AHA.