walking on the slope

Minetti, A.E., Moia, C., Roi, G.S., Susta, D, \& Guido Ferretti, G. \ \ 2001 \ \ Energy cost of walking and running at extreme uphill and downhill slopes. { \it Journal of Applied Physiology}, 93, 1039-1046.}は、トレイル・ランニングの熟達者10名に傾斜したトレッドミルを歩かせたり、走らせたりして、酸素消費量や二酸化炭素を測定してエネルギー消費を調べた。図~\ref{gradient_walking}が歩行の結果である。1938年のマルガリータの研究とよく一致している。傾斜が$-0.1$は10\%の下り坂で、この時にエネルギー消費が一番少ない。ただ、負の傾斜角に比例してエネルギー消費が増加し、$-25$\%以下になるとエネルギー消費が平坦地よりも増加する。一方、登りでは5\%で約2倍、10\%で約2.7倍と、登りの傾斜角に比例してエネルギー消費が増加する。

Abstract

The costs of walking (Cw) and running (Cr) were measured on 10 runners on a treadmill inclined between −0.45 to +0.45 at different speeds. The minimum Cw was 1.64 ± 0.50 J · kg−1 · m−1 at a 1.0 ± 0.3 m/s speed on the level. It increased on positive slopes, attained 17.33 ± 1.11 J · kg−1 · m−1 at +0.45, and was reduced to 0.81 ± 0.37 J · kg−1 · m−1 at −0.10. At steeper slopes, it increased to reach 3.46 ± 0.95 J · kg−1 · m−1 at −0.45. Cr was 3.40 ± 0.24 J · kg−1 · m−1 on the level, independent of speed. It increased on positive slopes, attained 18.93 ± 1.74 J · kg−1 · m−1 at +0.45, and was reduced to 1.73 ± 0.36 J · kg−1 · m−1 at −0.20. At steeper slopes, it increased to reach 3.92 ± 0.81 J · kg−1 · m−1 at −0.45. The mechanical efficiencies of walking and running above +0.15 and below −0.15 attained those of concentric and eccentric muscular contraction, respectively. The optimum gradients for mountain paths approximated 0.20–0.30 for both gaits. Downhill, Cr was some 40% lower than reported in the literature for sedentary subjects. The estimated maximum running speeds on positive gradients corresponded to those adopted in uphill races; on negative gradients they were well above those attained in downhill competitions.

Walking