Dicker S G, Lofthus G K, Thornton N W, Brooks G A
Med Sci Sports Exerc. 1980 Spring;12(1):20-3.
The purpose of this study was to investigate the respiratory and heart rate (fH) responses to tethered controlled frequency breathing (CFB) swimming. Controlled frequency breathing swimming is an aquatic training technique in which ventilatory rate is voluntarily reduced in order to induce systemic hypoxia during training. Nine elite college swimmers experienced with CFB were studied. The tethered swimming tests were discontinuous, with 4 min work bouts interspersed with equal duration rest periods. The resisting forces during tethered swimming were 5.63, 6.82, and 7.95 kg. Each subject was tested breathing every two (control), three, four, and five arm strokes. Subjects performed all four breathing frequencies at a constant arm stroke rate of 30/min during freestyle swimming. As ventilatory volume decreased due to CFB, O2 extraction and estimated tidal volume significantly increased (P less than .05) to maintain a constant O2 consumption for a given workload. Carbon dioxide production, respiratory exchange ratio, and fH did not change significantly in response to CFB. Estimated alveolar partial pressure of O2 (PAO2) decreased and PACO2 increased significantly during CFB. However, estimated saturation of arterial blood with O2 (SAO2) was essentially undiminished during CFB. These responses do not indicate hypoxia, but rather hypercapnia during CFB.
本研究的目的是调查对系留式控制频率呼吸（CFB）游泳的呼吸和心率（fH）反应。控制频率呼吸游泳是一种水上训练技术，在训练过程中通过主动降低通气频率来诱发全身性缺氧。对9名有CFB经验的精英大学生游泳运动员进行了研究。系留式游泳测试是间断进行的，4分钟的工作时段穿插着等时长的休息时段。系留式游泳时的阻力分别为5.63、6.82和7.95千克。每位受试者在自由泳时以每分钟30次的恒定划臂频率测试每两次（对照）、三次、四次和五次划臂时的呼吸情况。由于CFB导致通气量减少，氧气摄取量和估计潮气量显著增加（P小于0.05），以在给定工作量下维持恒定的氧气消耗量。二氧化碳产生量、呼吸交换率和fH对CFB没有显著变化。在CFB期间，估计的肺泡氧分压（PAO2）下降，PACO2显著升高。然而，在CFB期间，估计的动脉血氧饱和度（SAO2）基本未降低。这些反应并不表明缺氧，而是CFB期间的高碳酸血症。
