Background:The effects of moderate weight loss on operational lung volumes during exercise and the oxygen (O2) cost of breathing are unknown in obese women but could have important implications regarding exercise endurance.Methods:In 29 obese women (33±8 years, 97±14 kg, body mass index: 36±4 kg m-2, body fat: 45.6±4.5%; means±s.d.), body composition, fat distribution (by magnetic resonance imaging), pulmonary function, operational lung volumes during exercise and the O2 cost of breathing during eucapnic voluntary hyperpnea (([Vdot ]O2) vs ([Vdot ]E) slope) were studied before and after a 12-week diet and resistance exercise weight loss program.Results:Participants lost 7.5±3.1 kg or ≈8% of body weight (P2 cost of breathing was reduced by 16% (2.52±1.02–2.11±0.72 ml l-1; P=0.003). As a result, O2 uptake of the respiratory muscles ([Vdot ]O2Resp), estimated as the product of O2 cost of breathing and exercise ([Vdot ]E) during cycling at 60 W, was significantly reduced by 27±31 ml (P2) during cycling at 60 W.Conclusions:Moderate weight loss yields important improvements in respiratory function at rest and during submaximal exercise in otherwise healthy obese women. These changes in breathing load could have positive effects on the exercise endurance and adherence to physical activity.International Journal of Obesity advance online publication, 22 March 2016; doi:10.1038/ijo.2016.21.
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics
- Endocrinology, Diabetes and Metabolism