 Participants will complete up to four study visits. The first visit will involve completion of the informed consent process followed by a screening for study eligibility. The screening will consist of questionnaires pertaining to detailed medical history, diet, physical activity, and health-related quality of life KCCQ. Anthropometric measures and a general health screening including heart rate, resting blood pressure, and small blood 15 mL and urine samples will be collected. Volunteers meeting eligibility requirements will be scheduled for a screening maximal cardiopulmonary exercise test. Immediately prior to the exercise treadmill test, each subject will have a resting ECG and blood pressure to determine whether there are any abnormalities that would contraindicate exercise testing. Qualified subjects will then undergo a maximal cardiopulmonary exercise CPX test. 