Siegler Jason C, Marshall Paul W M, Raftry Sean, Brooks Cristy, Dowswell Ben, Romero Rick, Green Simon
Sport and Exercise Science, School of Science and Health, and.
J Appl Physiol (1985). 2013 Dec;115(11):1634-40. doi: 10.1152/japplphysiol.00688.2013. Epub 2013 Oct 3.
The purpose of this investigation was to assess the influence of sodium bicarbonate supplementation on maximal force production, rate of force development (RFD), and muscle recruitment during repeated bouts of high-intensity cycling. Ten male and female (n = 10) subjects completed two fixed-cadence, high-intensity cycling trials. Each trial consisted of a series of 30-s efforts at 120% peak power output (maximum graded test) that were interspersed with 30-s recovery periods until task failure. Prior to each trial, subjects consumed 0.3 g/kg sodium bicarbonate (ALK) or placebo (PLA). Maximal voluntary contractions were performed immediately after each 30-s effort. Maximal force (F max) was calculated as the greatest force recorded over a 25-ms period throughout the entire contraction duration while maximal RFD (RFD max) was calculated as the greatest 10-ms average slope throughout that same contraction. F max declined similarly in both the ALK and PLA conditions, with baseline values (ALK: 1,226 ± 393 N; PLA: 1,222 ± 369 N) declining nearly 295 ± 54 N [95% confidence interval (CI) = 84-508 N; P < 0.006]. RFD max also declined in both trials; however, a differential effect persisted between the ALK and PLA conditions. A main effect of condition was observed across the performance time period, with RFD max on average higher during ALK (ALK: 8,729 ± 1,169 N/s; PLA: 7,691 ± 1,526 N/s; mean difference between conditions 1,038 ± 451 N/s, 95% CI = 17-2,059 N/s; P < 0.048). These results demonstrate a differential effect of alkalosis on maximum force vs. maximum rate of force development during a whole body fatiguing task.
本研究的目的是评估补充碳酸氢钠对高强度自行车运动重复回合期间最大力量产生、力量发展速率（RFD）和肌肉募集的影响。十名男性和女性（n = 10）受试者完成了两项固定踏频的高强度自行车运动试验。每项试验包括一系列以峰值功率输出的120%（最大分级测试）进行的30秒努力，其间穿插30秒的恢复期，直至任务失败。在每次试验前，受试者服用0.3 g/kg碳酸氢钠（ALK）或安慰剂（PLA）。每次30秒努力后立即进行最大自主收缩。最大力量（F max）计算为整个收缩持续时间内25毫秒期间记录的最大力量，而最大RFD（RFD max）计算为同一收缩期间最大的10毫秒平均斜率。在ALK和PLA条件下，F max的下降情况相似，基线值（ALK：1226±393 N；PLA：1222±369 N）下降了近295±54 N [95%置信区间（CI）= 84 - 508 N；P < 0.006]。在两项试验中，RFD max也有所下降；然而，ALK和PLA条件之间存在差异效应。在整个运动时间段内观察到条件的主要效应，ALK期间RFD max平均更高（ALK：8729±1169 N/s；PLA：7691±1526 N/s；条件之间的平均差异为1038±451 N/s，95% CI = 17 - 2059 N/s；P < 0.048）。这些结果表明，在全身疲劳任务中，碱中毒对最大力量与最大力量发展速率有不同的影响。
