Buffering agents have not been comprehensively profiled in terms of their capacity to influence water retention prior to exercise. The purpose of this investigation was to profile the fluid retention characteristics of sodium bicarbonate (BIC) and sodium citrate (CIT) to determine the efficacy of these buffering mediums as hyperhydrating agents. Nineteen volunteers (13 males and six females; age = 28.3 ± 4.9 years) completed three trials (randomized and cross-over design). For each trial, a baseline measurement of body mass, capillary blood, and urine was collected prior to ingestion of their respective condition (control condition [CON] = 25 ml/kg artificially sweetened water; BIC condition = CON + 7.5 g/L of sodium in the form of BIC; CIT condition = CON + 7.5 g/L of sodium in the form of CIT). The fluid loads were consumed in four equal aliquots (0, 20, 40 and 60 min; fluid intake was 1.972 ± 361 ml [CON]; 1.977 ± 360 ml [BIC]; 1.953 ± 352 ml [CIT]). Samples were recorded at 20 (body mass and urine) and 60 min (blood) intervals for 180 min. Blood buffering capacity (HCO₃⁻) was elevated (p < .001) in both BIC (32.1 ± 2.2 mmol/L) and CIT (28.9 ± 3.8 mmol/L) at 180 min compared with CON (25.1 ± 1.8 mmol/L). Plasma volume expansion was greater (p < .001) in both BIC (8.1 ± 1.3%) and CIT (5.9 ± 1.8%) compared with CON (−1.1 ± 1.4%); whereas, total urine production was lower in BIC and CIT at 180 min (BIC vs. CON, mean difference of 370 ± 85 ml; p < .001; CIT vs. CON, mean difference of 239 ± 102 ml; p = .05). There were no increases observed in body mass (p = .9). Under resting conditions, these data suggest BIC and CIT induce a greater plasma hypervolemic response as compared with water alone.

缓冲剂在运动前影响水潴留的能力尚未得到全面的描述。本研究的目的是分析碳酸氢钠 (BIC) 和柠檬酸钠 (CIT) 的液体滞留特性，以确定这些缓冲介质作为超水合剂的功效。19 名志愿者（13 名男性和 6 名女性；年龄 = 28.3 ± 4.9 岁）完成了三项试验（随机和交叉设计）。对于每项试验，在摄入各自条件之前收集体重、毛细血管血液和尿液的基线测量值（对照条件 [CON] = 25 ml/kg 人工甜水；BIC 条件 = CON + 7.5 g/L BIC 形式的钠；CIT 条件 = CON + 7.5 g/L 的 CIT 形式的钠）。流体负荷分四等份消耗（0、20、40 和 60 分钟；流体摄入量为 1.972 ± 361 ml [CON]；1.977 ± 360 ml [BIC]；1.953 ± 352 ml [CIT]）。以 20 分钟（体重和尿液）和 60 分钟（血液）间隔记录样品 180 分钟。血液缓冲能力（HCO₃ ^- ) 在 180 分钟时 BIC (32.1 ± 2.2 mmol/L) 和 CIT (28.9 ± 3.8 mmol/L) 与 CON (25.1 ± 1.8 mmol/L) 相比升高 ( p < .001)。 与 CON (-1.1 ± 1.4%) 相比，BIC (8.1 ± 1.3%) 和 CIT (5.9 ± 1.8%) 的血浆体积膨胀更大 ( p < .001)；而在 180 分钟时，BIC 和 CIT 的总尿量较低（BIC 与 CON，平均差异为 370 ± 85 ml；p  < .001；CIT 与 CON，平均差异为 239 ± 102 ml；p  = .05 ）。没有观察到体重增加（p  = .9）。在静息条件下，这些数据表明与单独的水相比，BIC 和 CIT 诱导更大的血浆高血容量反应。