Weight loss reduces dyspnea on exertion in obese women

• Moderate weight loss effectively reduced dyspnea on exertion (DOE) in obese women.
• Oxygen cost of breathing decreased following weight loss.
• Body composition and pulmonary function improved with weight loss.
• Reduction in DOE was not significantly associated with physiological changes measured.

During submaximal exercise, some otherwise healthy obese women experience breathlessness, or dyspnea on exertion (+DOE), while others have mild or no DOE (−DOE). We investigated whether weight loss could reduce DOE. Twenty nine obese women were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60 W cycling: +DOE (n = 14, RPB ≥ 4, 34 ± 8 years, and 36 ± 3 kg/m2) and −DOE (n = 15, RPB ≤ 2, 32 ± 8 years, and 36 ± 4 kg/m2) and then completed a 12-week weight loss program. Both groups lost a moderate amount of weight (+DOE: 6.6 ± 2.4 kg, −DOE: 8.4 ± 3.5 kg, and p < 0.001). RPB decreased significantly in the +DOE group (from 4.7 ± 1.1 to 3.1 ± 1.6) and remained low in the −DOE (from 1.5 ± 0.7 to 1.6 ± 1.1) (interaction p < 0.002). Most physiological variables measured (i.e. body composition, fat distribution, pulmonary function, oxygen cost of breathing, and cardiorespiratory measures) improved with weight loss; however, the decrease in RPB was not correlated with any of these variables (p > 0.05). In conclusion, moderate weight loss was effective in reducing breathlessness on exertion in obese women who experienced DOE at baseline.