Institute of Human Nutrition and Dietetics, Poznań University of Life Sciences, Poznań, Poland.
Department of Biochemistry, University School of Physical Education in Poznan, Poznań, Poland.
PLoS One. 2018 May 17;13(5):e0197480. doi: 10.1371/journal.pone.0197480. eCollection 2018.
Sodium bicarbonate (SB) has been proposed as an ergogenic aid, as it improves high-intensity and resistance exercise performance. However, no studies have yet investigated SB application in CrossFit. This study examined the effects of chronic, progressive-dose SB ingestion on CrossFit-like performance and aerobic capacity.
In a randomized, double-blind, cross-over trial, 21 CrossFit-trained participants were randomly allocated to 2 groups and underwent 2 trials separated by a 14-day washout period. Participants ingested either up to 150 mg∙kg-1 of SB in a progressive-dose regimen or placebo for 10 days. Before and after each trial, Fight Gone Bad (FGB) and incremental cycling (ICT) tests were performed. In order to examine biochemical responses, blood samples were obtained prior to and 3 min after completing each exercise test.
No gastrointestinal (GI) side effects were reported during the entire protocol. The overall FGB performance improved under SB by 6.1% (p<0.001) and it was ~3.1% higher compared to post placebo (PLApost) (p = 0.040). The number of repetitions completed in each round also improved under SB (mean from baseline: +5.8% to +6.4%). Moreover, in ICT, the time to ventilatory threshold (VT) (8:25 min SBpost vs. 8:00 min PLApost, p = 0.020), workload at VT (218 W SBpost vs. 208 W PLApost, p = 0.037) and heart rate at VT (165 bpm SBpost vs. 161 bpm PLApost, p = 0.030) showed higher SBpost than PLApost. Furthermore, the maximum carbon dioxide production increased under SB by ~4.8% (from ~3604 mL∙min-1 to ~3776 mL∙min-1, p = 0.049). Pyruvate concentration and creatine kinase activity before ICT showed higher SBpost than PLApost (0.32 mmol∙L-1 vs. ~0.26 mmol∙L-1, p = 0.001; ~275 U∙L-1 vs. ~250 U∙L-1, p = 0.010, respectively). However, the small sample size limits the wide-application of our results.
Progressive-dose SB ingestion regimen eliminated GI side effects and improved CrossFit-like performance, as well as delayed ventilatory threshold occurrence.
碳酸氢钠（SB）已被提议作为一种运动补剂，因为它可以提高高强度和抗阻运动的表现。然而，目前还没有研究调查 SB 在 CrossFit 中的应用。本研究旨在研究慢性、渐进剂量 SB 摄入对 CrossFit 样运动表现和有氧能力的影响。
在一项随机、双盲、交叉试验中，21 名接受过 CrossFit 训练的参与者被随机分配到 2 组，并在 14 天的洗脱期后进行 2 次试验。参与者在 10 天内分别摄入高达 150mg·kg-1的 SB 或安慰剂。在每次试验前后，进行 Fight Gone Bad（FGB）和递增循环（ICT）测试。为了检查生化反应，在每次运动测试完成前和完成后 3 分钟采集血样。
整个方案中未报告胃肠道（GI）副作用。在 SB 下，整体 FGB 表现提高了约 6.1%（p<0.001），比 PLAPost 高约 3.1%（p=0.040）。每个轮次完成的重复次数也有所提高（从基线的平均增加：+5.8%至+6.4%）。此外，在 ICT 中，达到通气阈值（VT）的时间（8:25 分钟 SBpost 比8:00 分钟 PLApost，p=0.020）、VT 时的工作量（218 W SBpost 比208 W PLApost，p=0.037）和 VT 时的心率（165 bpm SBpost 比161 bpm PLApost，p=0.030）SBpost 高于 PLApost。此外，SB 下的最大二氧化碳产量增加了约 4.8%（从3604 mL·min-1 增加到3776 mL·min-1，p=0.049）。ICT 前的丙酮酸浓度和肌酸激酶活性显示 SBpost 高于 PLApost（0.32 mmol·L-1 比0.26 mmol·L-1，p=0.001；275 U·L-1 比250 U·L-1，p=0.010）。然而，小样本量限制了我们结果的广泛应用。
渐进剂量 SB 摄入方案消除了 GI 副作用，提高了 CrossFit 样运动表现，并延迟了通气阈值的发生。
