Inclusion Criteria:  20-29 years of age  Exclusion Criteria:  Pregnancy Children Inmates Neuromotor, musculoskeletal, or rheumatoid disorders that are exacerbated by exercise or conditions preventing cooperation Contraindications to Symptom-limited Maximal Exercise Testing Metabolic disease Pacemakers/Implantable devices Supplemental Oxygen use Diagnosis of severe arterial hypertension Uncontrolled asthma