In the first visit, various anthropometric data are collected from participants, such as height, weight, and waist and hip circumference. The participants' blood pressure is also checked for hypertension. The participants are given Dual Energy X-Ray Absorptiometry (DEXA) scans to determine total body composition (bone, fat, and fat-free mass) If the participant is female, a urine analysis to determine pregnancy is required during the visit before the DEXA to ensure safety. Participants are given the Rapid Assessment of Physical Activity (RAPA) questionnaire to assess habitual activity levels. The participants' muscle strength is also measured using the Biodex System 3, an isokinetic dynamometer. The participants then undergo a maximal stress test on a treadmill integrated with a Cardinal Health Metabolic/ECG cart using a modified Balke protocol, beginning at 3 mph, 0% grade, and increasing 2.5% grade every 3 minutes. The ECG component of the metabolic cart will be used for continuous heart rate monitoring as part of the fitness assessment. Cardiorespiratory parameters (VO2, ventilation, respiratory rate) will also be measured throughout the test. Blood pressure is measured during the last 30 seconds of each exercise stage and the rating of perceived exertion (RPE) using the Borg 6 to 20 scale is obtained during each stage. Subjects are urged to give a maximal effort and are pushed until volitional fatigue.