Exercise Induced Changes in Fat Metabolism

If eligible to participate in the research study after completing the physical screening procedures, participants will be asked to return to the Substrate Metabolism Laboratory on another occasion after a short fast (no food or beverages - besides water) for at least 6 hours. After participants arrive, participants will rest quietly for approximately 30 min. The investigators will then collect a blood sample from a vein in participants hand, or forearm. After obtaining a baseline blood sample, participants will exercise at a moderate intensity (on a treadmill or a stationary bike) for one hour. This one hour moderate exercise session will feel like a slow jog during which participants would be able to carry a conversation. In order for the investigators to measure energy expended and the amount of fat participants are burning during exercise, the investigators will periodically ask participants to breathe through a mouthpiece so the investigators can collect participants expired breath. After the exercise session the investigators will collect another blood sample from a vein in participants hand, or forearm.