Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
Foundation for Dive Research (SDR), Aerdenhout, The Netherlands.
Undersea Hyperb Med. 2021 Fourth Quarter;48(4):377-382.
Swimming requires frequent lifting and rotating of the head to inhale. A snorkeler saves energy by avoiding this maneuver, but the snorkel adds breathing work due to air flow resistance. The needed power of these head movements has never been examined, although the extra power of breathing through a snorkel was studied recently. This study aimed: 1) to model the work of vertically lifting and rotating in comparison with the breathing work added by a snorkel; 2) to compare heart rate (HR) and velocity (v) while swimming under both conditions; 3) to evaluate the results for surface-swimming divers. Presumably the power when using a snorkel is less, and the difference in power predicts the difference in swimming velocity. Kinematics of head lifting and rotation, and the difference between the hydrodynamics were modeled. A swim test lasting 12 minutes at maximum speed (Cooper swim test) was performed in a pool by nine recreational divers in the front crawl style, with face mask but without fins. All subjects performed the test both with and without snorkel. The average velocity with a snorkel, 0.72±0.09 m·s-¹, was 4.4±3.9% higher than without (p=0.008), but HR (144±16bpm) showed no difference (0.8±3.4%). The model based on our subjects' performance showed that 7.5% of the total power is spent in the inhaling maneuver while crawling and 2.7% while snorkeling. Theoretically this would allow the snorkeler to swim 5.2% faster. It is concluded that snorkeling is energetically advantageous as well as for divers swimming on the surface.
游泳需要频繁地抬头和转头来吸气。潜水员通过避免这种动作来节省体力，但由于空气流动阻力，通气管会增加呼吸的工作量。虽然最近研究了通过通气管呼吸的额外功率，但这些头部运动所需的功率从未被检查过。本研究旨在：1）与通气管增加的呼吸功相比，模拟垂直提升和旋转的功；2）比较两种情况下游泳时的心率（HR）和速度（v）；3）评估水面游泳潜水员的结果。使用通气管时的功率可能较低，功率差预测游泳速度差。对头颈提升和旋转的运动学以及水动力学之间的差异进行了建模。在泳池中，九位休闲潜水员以自由泳姿势进行了持续 12 分钟的最大速度（库珀游泳测试）游泳测试，戴着面罩但不戴脚蹼。所有受试者均进行了有和没有通气管的测试。使用通气管的平均速度为 0.72±0.09 m·s-¹，比不使用时高 4.4±3.9%（p=0.008），但心率（144±16bpm）没有差异（0.8±3.4%）。基于我们研究对象表现的模型表明，在爬行时，吸气动作消耗了总功率的 7.5%，而在使用通气管时则消耗了 2.7%。理论上，这将使使用通气管的潜水员游泳速度快 5.2%。因此，可以得出结论，通气管在潜水员在水面游泳时具有能量优势。
