At the first visit you will complete questionnaires about your quality of life, medical conditions, and how physically active you are currently and have been in the past. The questionnaires will take about 45 minutes to complete. A baseline electrocardiogram (ECG-a test to measure the electrical activity of the heart) will be performed. If your ECG test is not normal you will be informed. You will practice using the exercise bicycle that will be used in the fitness testing at the later visits. You will be asked to provide a saliva sample by placing a cotton roll in your mouth until it is saturated and then placing it back in a plastic vial without using your hands. This sample will be for practice and will be discarded.