Pendergast D, Zamparo P, di Prampero P E, Capelli C, Cerretelli P, Termin A, Craig A, Bushnell D, Paschke D, Mollendorf J
Department of Physiology, University at Buffalo, 124 Sherman Hall, Buffalo, NY 14214, USA.
Eur J Appl Physiol. 2003 Oct;90(3-4):377-86. doi: 10.1007/s00421-003-0919-y. Epub 2003 Sep 2.
In this paper a complete energy balance for water locomotion is attempted with the aim of comparing different modes of transport in the aquatic environment (swimming underwater with SCUBA diving equipment, swimming at the surface: leg kicking and front crawl, kayaking and rowing). On the basis of the values of metabolic power (E), of the power needed to overcome water resistance (Wd) and of propelling efficiency (etaP=Wd/Wtot, where Wtot is the total mechanical power) as reported in the literature for each of these forms of locomotion, the energy cost per unit distance (C=E/v, where v is the velocity), the drag (performance) efficiency (etad=Wd/E) and the overall efficiency (etao=Wtot/E=etad/etaP) were calculated. As previously found for human locomotion on land, for a given metabolic power (e.g. 0.5 kW=1.43 l.min(-1) VO2) the decrease in C (from 0.88 kJ.m(-1) in SCUBA diving to 0.22 kJ.m(-1) in rowing) is associated with an increase in the speed of locomotion (from 0.6 m.s(-1) in SCUBA diving to 2.4 m.s(-1) in rowing). At variance with locomotion on land, however, the decrease in C is associated with an increase, rather than a decrease, of the total mechanical work per unit distance (Wtot, kJ.m(-1)). This is made possible by the increase of the overall efficiency of locomotion (etao=Wtot/E=Wtot/C) from the slow speeds (and loads) of swimming to the high speeds (and loads) attainable with hulls and boats (from 0.10 in SCUBA diving to 0.29 in rowing).
本文尝试对水上运动进行完整的能量平衡分析，目的是比较水生环境中的不同运输方式（使用水肺潜水装备在水下游泳、在水面游泳：腿部打水和自由泳、皮划艇和划船）。根据文献中报道的每种运动形式的代谢功率（E）、克服水阻力所需的功率（Wd）和推进效率（etaP = Wd / Wtot，其中Wtot是总机械功率），计算了每单位距离的能量消耗（C = E / v，其中v是速度）、阻力（性能）效率（etad = Wd / E）和整体效率（etao = Wtot / E = etad / etaP）。正如之前在人类陆地运动中所发现的那样，对于给定的代谢功率（例如0.5千瓦 = 1.43升·分钟⁻¹ 耗氧量），C的降低（从水肺潜水时的0.88千焦·米⁻¹降至划船时的0.22千焦·米⁻¹）与运动速度的增加（从水肺潜水时的0.6米·秒⁻¹增加到划船时的2.4米·秒⁻¹）相关。然而，与陆地运动不同的是，C的降低与每单位距离总机械功（Wtot，千焦·米⁻¹）的增加而非减少相关。这是通过运动整体效率（etao = Wtot / E = Wtot / C）的提高实现的，从游泳的低速（和负荷）到船体和船只可达到的高速（和负荷）（从水肺潜水时的0.10增加到划船时的0.29）。
