Energetics of vertical kilometer foot races; is steeper cheaper?
Autor: | Nicola Giovanelli, Keely Henninger, Rodger Kram, Amanda Louise Ryan Ortiz |
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Rok vydání: | 2016 |
Předmět: |
Adult
Male 030110 physiology 0301 basic medicine medicine.medical_specialty Power walking Physiology Walking Running 03 medical and health sciences Oxygen Consumption 0302 clinical medicine Kilometer Physiology (medical) medicine Humans Foot Energetics Elevation 030229 sport sciences Geodesy Physical therapy Female Basal Metabolism Energy Metabolism Locomotion Geology Foot (unit) |
Zdroj: | Journal of Applied Physiology. 120:370-375 |
ISSN: | 1522-1601 8750-7587 |
Popis: | Vertical kilometer foot races consist of a 1,000-m elevation gain in vert) and running (Crvert). Using video analysis, we determined stride frequency, stride length, and duty factor (fraction of stride that each foot is in ground contact). At all angles other than 9.4°, Cwvertwas cheaper than Crvert(average −8.45 ± 1.05%; P < 0.001). Further, broad minima for both Cwvertand Crvertexisted between 20.4 and 35.0° (average Cwvert44.17 ± 0.41 J·kg−1·m−1and average Crvert48.46 ± 0.35 J·kg−1·m−1). At all angles and speeds tested, both walking and running involved having at least one foot on the ground at all times. However, in walking, stride frequency and stride length were ∼28% slower and longer, respectively, than in running. In conclusion, we found that there is a range of angles for which energy expenditure is minimized. At the vertical velocity tested, on inclines steeper than 15.8°, athletes can reduce their energy expenditure by walking rather than running. |
Databáze: | OpenAIRE |
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