Swain D P, Coast J R, Clifford P S, Milliken M C, Stray-Gundersen J
J Appl Physiol (1985). 1987 Feb;62(2):668-72. doi: 10.1152/jappl.1987.62.2.668.
Energy in bicycling is primarily expended to overcome air resistance, which is proportional to a cyclist's surface area (SA). Thus we hypothesized that large cyclists should have a lower O2 consumption normalized to body weight (VO2/BW) than small cyclists because of the former's lower SA/BW. We measured the VO2/BW of small (BW = 59.4 +/- 4.1 kg) and large (BW = 84.4 +/- 3.2 kg) cyclists while they bicycled on a flat road at 10, 15, and 20 mph. The large cyclists had a 22% lower VO2/BW than the small cyclists at all speeds. However, the SA/BW ratio of the large cyclists was only 11% lower than that of the small cyclists. We then photographically determined the frontal area (FA) of the cyclists in a racing posture, and found that the large cyclists had a 16% lower FA/BW ratio than the small cyclists. We conclude that large cyclists are at a distinct advantage, in terms of VO2/BW, while bicycling on level roads, and this advantage is principally due to their lower FA/BW ratio.
骑自行车时的能量主要用于克服空气阻力，而空气阻力与骑车人的表面积（SA）成正比。因此我们推测，体型较大的骑车人相对于体重的耗氧量（VO2/BW）应该比体型较小的骑车人低，因为前者的体表面积与体重比（SA/BW）较低。我们测量了体型较小（体重 = 59.4 +/- 4.1千克）和体型较大（体重 = 84.4 +/- 3.2千克）的骑车人在平坦道路上以10、15和20英里/小时的速度骑行时的VO2/BW。在所有速度下，体型较大的骑车人的VO2/BW都比体型较小的骑车人低22%。然而，体型较大的骑车人的SA/BW比仅比体型较小的骑车人低11%。然后我们通过摄影确定了骑车人处于比赛姿势时的 frontal area（FA），发现体型较大的骑车人的FA/BW比比体型较小的骑车人低16%。我们得出结论，就VO2/BW而言，体型较大的骑车人在平坦道路上骑行时具有明显优势，而这种优势主要归因于他们较低的FA/BW比。 （注：原文中frontal area未给出准确中文释义，暂保留英文）
