Sheard P W, Haughey H
Division of Sport and Exercise Sciences, University of Bedfordshire, Bedfordshire, UK.
Undersea Hyperb Med. 2007 Mar-Apr;34(2):91-7.
The purpose of this study was to examine the effects of orally ingested sodium bicarbonate (NaHCO3) on voluntary breath-hold time with facial immersion. Eight non-elite breath-hold divers aged 20-41 (26.75 +/- 7.83 years) were recruited to undertake two bouts of three monitored, facial-immersion breath-holds, one week apart. Subjects were randomly allocated to double-blind sessions of ingesting an experimental (0.3 g x kg(-1) NaHCO3) or placebo (8 g NaCl) solution. Heart rate, pre- and post-breath-hold end-tidal gases, peripheral oxygen saturation (SpO2) at right index finger and maximum breath-hold times (Max-BHT) were recorded. Max-BHT was established during the third breath-hold in both trials. Max-BHT of 168.2 (+/- 20.7) sec and 145.7 (+/- 21.4) see were recorded for the experimental and placebo conditions, respectively (P = 0.019). Average bradycardic response did not differ between the experimental and placebo trials (P = 0.166). Whilst there was a significant difference in post-breath-hold end-tidal oxygen (P(ET) O2), one was not noted in end-tidal carbon dioxide (P(ET) CO2) measures (P = 0.048, and; P = 0.530, respectively). There was significant difference in lowest recorded SpO2 (P = 0.008) between the trials. It is suggested that ingestion of NaHCO3, prior to facially immersed breath-holds, has an ergogenic effect, prolonging Max-BHT by approximately 8.6%.
本研究的目的是考察口服碳酸氢钠（NaHCO₃）对面部浸入水中时自愿屏气时间的影响。招募了8名年龄在20 - 41岁（26.75 ± 7.83岁）的非精英屏气潜水者，进行两轮三次有监测的面部浸入水中屏气试验，间隔一周。受试者被随机分配到双盲试验组，分别摄入实验溶液（0.3 g×kg⁻¹ NaHCO₃）或安慰剂（8 g NaCl）溶液。记录心率、屏气前后的呼气末气体、右手食指的外周血氧饱和度（SpO₂）以及最大屏气时间（Max - BHT）。在两次试验的第三次屏气时确定Max - BHT。实验条件和安慰剂条件下的Max - BHT分别记录为168.2（±20.7）秒和145.7（±21.4）秒（P = 0.019）。实验试验和安慰剂试验之间的平均心动过缓反应没有差异（P = 0.166）。虽然屏气后呼气末氧气（P（ET）O₂）有显著差异，但在呼气末二氧化碳（P（ET）CO₂）测量中未发现差异（分别为P = 0.048和P = 0.530）。两次试验之间记录到的最低SpO₂有显著差异（P = 0.008）。研究表明，在面部浸入水中屏气前摄入NaHCO₃具有促力效应，可使Max - BHT延长约8.6%。
