For the aerobic interval exercise condition, subjects will be equipped with a heart rate (HR) monitor and asked to perform an interval exercise bout on a cycle ergometer. To warm up, subjects will cycle at a work rate associated with 50% HRmax for 10 minutes. Wattage will then increase and subjects will do four 4-minute intervals at a work rate associated with 90%-95% HRmax, separated by 3 minutes of active recovery at a work rate associated with 50% HRmax. Subjects will be given a 5-minute cool-down period at a work rate associated with 50% HRmax. After the exercise, subjects will remain in the lab for 4 hours and their blood pressure will be measured every 10 minutes using the Oscar 2 with SphygmoCor ambulatory blood pressure system, and cardiac output measured in 10-second averages using the PhysioFlow. During this time, subjects will remain seated with their body posture maintained constant.