Zamparo P, Gatta G, Pendergast D, Capelli C
Dipartimento di Scienze Neurologiche e della Visione, Strada le Grazie 8, 37134, Verona, Italy.
Eur J Appl Physiol. 2009 May;106(2):195-205. doi: 10.1007/s00421-009-1007-8. Epub 2009 Feb 18.
The aim of this study was to investigate the role of trunk incline (TI) and projected frontal area (A(eff)) in determining drag during active/passive measurements. Active drag (D(a)) was measured in competitive swimmers at speeds from 0.6 to 1.4 m s(-1); speed specific drag (D(a)/v(2)) was found to decrease as a function of v (P < 0.001) to indicate that the human body becomes more streamlined with increasing speed. Indeed, both A(eff) and TI were found to decrease with v (P < 0.001) whereas C(d) (the drag coefficient) was found to be unaffected by v. These data suggest that speed specific drag depend essentially on A(eff). Additional data indicate that A(eff) is larger during front crawl swimming than during passive towing (0.4 vs. 0.24 m(2)). This suggest that D(a)/v(2) is larger than D(p)/v(2) and, at a given speed, that D(a) is larger than D(p).
本研究的目的是调查躯干倾斜度（TI）和投影 frontal 面积（A(eff)）在主动/被动测量过程中对阻力的影响。在竞技游泳运动员中测量了速度范围为0.6至1.4 m s(-1)时的主动阻力（D(a)）；发现速度比阻力（D(a)/v(2)）随速度 v 的增加而降低（P < 0.001），这表明人体随着速度的增加变得更加流线型。实际上，发现 A(eff)和 TI 均随速度 v 降低（P < 0.001），而阻力系数 C(d)不受速度 v 的影响。这些数据表明速度比阻力主要取决于 A(eff)。其他数据表明，自由泳时的 A(eff)大于被动拖曳时的 A(eff)（0.4 平方米对 0.24 平方米）。这表明 D(a)/v(2)大于 D(p)/v(2)，并且在给定速度下，D(a)大于 D(p)。
