Institute of Exercise Biology and Physiotherapy, Centre of Behavioural and Health Sciences, University of Tartu , Tartu, Estonia.
J Sports Sci Med. 2008 Mar 1;7(1):125-31. eCollection 2008.
The purpose of the study was to assess the effects of sodium citrate ingestion on the metabolic response to exercise and performance in a 1500-m competitive run in trained female middle-distance runners in field conditions. Seventeen athletes (mean (± SD) aged 18.6 ± 2.5 years, VO2max 55.2 ± 7.6 ml·kg(-1)·min(-1)) competed in two 1500-m races following ingestion of 0.4 g·kg(-1) body mass of sodium citrate (CIT) and placebo (PLC - 1.0% solution of NaCl). The two substances, CIT and PLC were administered in 800 ml of solution in a randomly assigned double-blind crossover manner. Capillary blood samples were analysed for lactate, glucose, haemoglobin and haematocrit before administering the solutions (baseline) as well as before and after both 1500-m races. The athletes' times for trials CIT and PLC were 321.4 ± 26.4 and 317.4 ± 22.5 s, respectively (p > 0.05). A greater relative increase in plasma volume after administering the experimental solution, an increased body mass (by 0.4 kg; p = 0.006) immediately before the race and a restrained increase in blood glucose concentration (by 2.5 ± 1.2 mmol·l(-1) vs 3.4 ± 0.8 mmol·l(-1); p = 0.002) during the race were observed in the CIT trial compared to the PLC. A significant relationship was observed between body mass of the subjects immediately before the race and performance time (r = 0.374; p = 0.029). There were no between-treatment differences in heart rate in any stage of the run or in blood lactate accumulation during the race (final concentration of lactate was 14.4 ± 3.0 mmol·l(-1) and 13.4 ± 2.5 mmol·l(-1) (p > 0.05) in the CIT and PLC trials, respectively). The results suggest that sodium citrate induces an increase in water retention before exercise and may modify carbohydrate metabolism in high intensity running, but does not improve performance in 1500-m competitive run in female middle-distance runners. Key pointsPrevious studies have found that sodium bicarbonate administration may enhance performance in male athletes in running distances of 400-1500 m.The use of sodium bicarbonate in competitive sports is limited because it induces gastrointestinal distress in many subjects.The limited data on the effects of sodium citrate ingestion on the metabolic response to exercise and performance suggest that it may have all the benefits of sodium bicarbonate without the associated negative side effects.We assessed the effects of sodium citrate ingestion on the metabolic response to exercise and performance in a 1500-m competitive run in trained young female middle-distance runners.The results suggest that sodium citrate induces an increase in water retention before exercise and may modify carbohydrate metabolism in high intensity running, but does not improve performance in 1500-m competitive run in female middle-distance runners.
研究目的在于评估在野外条件下，17 名受训的女性中长跑运动员进行 1500 米竞赛跑时，摄入柠檬酸纳对运动代谢反应和运动表现的影响。运动员（平均年龄为 18.6 ± 2.5 岁，最大摄氧量为 55.2 ± 7.6 ml·kg(-1)·min(-1)）服用 0.4 g·kg(-1)体重的柠檬酸纳（CIT）和安慰剂（PLC - 1.0%氯化钠溶液）后，分别参加了两次 1500 米比赛。两种物质 CIT 和 PLC 以 800 ml 溶液的形式随机双盲交叉给药。在给予溶液之前（基线）以及两次 1500 米比赛前后，对毛细血管血样进行分析，以检测乳酸、葡萄糖、血红蛋白和血细胞比容。CIT 和 PLC 组运动员的成绩分别为 321.4 ± 26.4 和 317.4 ± 22.5 s（p > 0.05）。与 PLC 相比，CIT 组在实验溶液给药后表现出更大的血浆容量相对增加，比赛前即刻体重增加（增加 0.4 公斤；p = 0.006），以及运动期间血糖浓度（增加 2.5 ± 1.2 mmol·l(-1)比 3.4 ± 0.8 mmol·l(-1)；p = 0.002）受到抑制。与比赛前即刻的体重相比，运动员的表现时间（r = 0.374；p = 0.029）与表现时间呈显著相关。在跑步的任何阶段，CIT 和 PLC 组的心率或比赛中血乳酸的积累均无治疗间差异（最终乳酸浓度分别为 14.4 ± 3.0 mmol·l(-1)和 13.4 ± 2.5 mmol·l(-1)（p > 0.05））。结果表明，柠檬酸纳可在运动前增加水潴留，并可能改变高强度跑步中的碳水化合物代谢，但不能提高女性中长跑运动员 1500 米竞赛跑的表现。关键要点：先前的研究发现，碳酸氢钠的给药可能会提高男性运动员在 400-1500 米跑中的表现。由于碳酸氢钠会引起许多受试者的胃肠道不适，因此在竞技体育中使用受到限制。关于柠檬酸纳摄入对运动代谢反应和运动表现的影响的有限数据表明，它可能具有碳酸氢钠的所有益处，而没有相关的负面副作用。我们评估了在训练有素的年轻女性中长跑运动员进行 1500 米竞赛跑时，柠檬酸纳摄入对运动代谢反应和运动表现的影响。结果表明，柠檬酸纳可在运动前增加水潴留，并可能改变高强度跑步中的碳水化合物代谢，但不能提高女性中长跑运动员 1500 米竞赛跑的表现。
