Morais Jorge E, Marinho Daniel A, Bartolomeu Raul F, Barbosa Tiago M
Department of Sports Sciences, Instituto Politécnico de Bragança, Bragança, Portugal.
Research Center in Sports, Health, and Human Development (CIDESD), Covilhã, Portugal.
J Hum Kinet. 2023 Nov 28;92:19-27. doi: 10.5114/jhk/172492. eCollection 2024 Apr.
The main objective of this study was to confirm that the passive drag coefficient is less dependent on swimming speed than the passive drag, Froude, and Reynolds numbers, even as swimming speed increases. The sample consisted of 12 young proficient non-competitive swimmers (seven males and five females: 20.4 ± 1.9 years). Passive drag was measured with a low-voltage isokinetic engine at 1.2, 1.4, 1.6 and 1.8 m/s. The frontal surface area was measured using digital photogrammetry. Passive drag showed significant differences with a strong effect size over the four towing speeds measured (F = 116.84, p < 0.001, η = 0.91) with a quadratic relationship with speed. The Froude and Reynolds numbers had similar trends, but with linear relationships. Conversely, the passive drag coefficient showed non-significant differences across the four towing speeds (F = 3.50, p = 0.062, η = 0.33). This strongly suggests that the passive drag coefficient should be the variable of choice for monitoring the hydrodynamic profile of swimmers rather than the absolute value of passive drag.
本研究的主要目的是证实，即使游泳速度增加，被动阻力系数比被动阻力、弗劳德数和雷诺数对游泳速度的依赖性更小。样本包括12名熟练的非竞技青年游泳者（7名男性和5名女性，年龄20.4±1.9岁）。使用低压等动发动机在1.2、1.4、1.6和1.8米/秒的速度下测量被动阻力。使用数字摄影测量法测量正面表面积。在测量的四种拖曳速度下，被动阻力显示出显著差异，效应量较大（F = 116.84，p < 0.001，η = 0.91），与速度呈二次关系。弗劳德数和雷诺数有类似趋势，但呈线性关系。相反，在四种拖曳速度下，被动阻力系数显示出不显著差异（F = 3.50，p = 0.062，η = 0.33）。这有力地表明，被动阻力系数应是监测游泳者水动力轮廓的首选变量，而非被动阻力的绝对值。
