Cardiorespiratory Responses to Treadmill Running at Different Slopes

The purpose of this study is: i) to determine if maximal oxygen uptake in downhill running is significantly different versus flat or uphill running, and ii) to compare cardiorespiratory and muscle fatigue responses to uphill vs flat and downhill running at similar running velocity and similar metabolic power. The investigators hypothesized that maximal oxygen uptake will be lower in downhill running. The investigators also anticipate attenuated cardiorespiratory and muscle fatigue responses to downhill running when compared to flat or uphill running performed at similar velocity but not when the comparison is done at similar metabolic power.