Metabolic, Cardiovascular, and Kinematic Responses to Running on Sloping Surfaces

Abstract

PURPOSE: The purpose of this study was to compare metabolic, cardiovascular, and kinematic responses to running on sloping surfaces between two groups of runners who varied in performance ability. METHODS: Trained collegiate runners were divided into a top (T; N = 7) and non-top (NT; N = 6) group based on 8-km performance time. Metabolic (indirect calorimetry), heart rate (HR, telemetry), stride frequency (SR, stop watch) and length (SL) were monitored during the following: 1) 20 min level run at 14.4 km·hr−1 followed by a run to exhaustion, 2) 20 min sloping-surface run at 14.4 km·hr−1, and 3) a 3 km performance run over sloping surfaces. RESULTS: VO2max for T (65.17 ± 1.85 mL·kg−1·min−1) was greater than NT (58.59 ± 0.44 mL·kg−1·min−1) (P<0.05). T maintained a faster velocity (4.77+0.08 m.s−1) compared to NT (4.04+0.18) (P<0.05) during the 3-km performance run with T sustaining a greater %VO2max (86.1 ± 1.7 vs. 80.8 ± 1.4%) (P<0.05); however, both groups had a similar oxygen cost per distance covered (T, 195.9 ± 3.4; NT, 196.7 ± 6.0 mL·kg−1·km−1) (P>0.05). Relative to level running, downhill and uphill running similarly decreased and increased VO2 and HR in both groups (P > 0.05), although T reached steady-rate quicker (P < 0.05), suggesting a faster rate of metabolic adjustment. SL was longer (P < 0.05) and shorter (P < 0.05) during downhill and uphill running, respectively, compared to level running for both groups. CONCLUSIONS: This study suggests uphill and downhill running similarly affect runners of different abilities, and that superior running performance over sloping surfaces is not attributable to running economy, but rather to a greater VO2max and ability to sustain a high %VO2max.