Mechanisms for Dyspnea on Exertion in Children With Obesity and Asthma: Distinct Physiological Phenotypes

General inclusion criteria: * Age range: 9-17 years of age * Participants with physician diagnosed asthma will be recruited for this study. * Objectively Confirmed Asthma Diagnosis: Asthma diagnosis will be confirmed objectively using spirometry (FEV1 \< 80% predicted or FEV1/FVC \< lower limit of normal), bronchodilator reversibility testing (post-bronchodilator improvement of ≥ 12% and 200mL in FEV1 or FVC; or a decrease in lung hyperinflation of at least 150 mL; ATS guidelines on lung function test interpretation). Patients in whom asthma cannot be confirmed objectively will be excluded from the study. * Experience dyspnea on exertion as assessed by answering "yes" to one of the following two questions on the screening questionnaire: 1) Do you get short of breath with exertion? 2) Do you feel that your asthma is limiting you from participating in exercise? * Ability to communicate in English Body mass index criteria (BMI): We will study asthmatic children with obesity based on their BMI percentile: • Obese: BMI ≥95th percentile and less than 170% of the 95th BMI percentile based on norms from the CDC Exclusion criteria: Criteria for pulmonary function: We will exclude asthmatic children with: * Severe asthma: Forced expiratory volume in 1s (FEV1) \< 50% predicted * Restrictive pulmonary disease: Forced vital capacity (FVC) and total lung capacity (TLC) \< 80% predicted * Diffusion limitation: Diffusing capacity relative to alveolar volume (DLCO/VA) \< 80% predicte…