 Participants will arrive at the lab having consumed a standardized breakfast. Prior to the downhill run, measures of pulse wave velocity PWV, heart rate variability HRV, flow mediated dilatation FMD will be collected according to the protocols to follow. Participants will then perform a 40 minute downhill run at a grade of -12 percent using a speed that elicits a VO2 of approximately 60 of the maximum value achieved during the max test. 