Department of Exercise Science and Pre-Health Professions, Creighton University, Omaha, NE 68178, USA.
Nutrients. 2021 May 27;13(6):1823. doi: 10.3390/nu13061823.
This investigation aimed to determine the effect of a multi-ingredient pre-workout supplement (MIPS) on heart rate (HR), perceived exertion (RPE), lactate concentration, and time to fatigue (TTF) during a running task to volitional exhaustion. Eleven NCAA Division I cross-country runners (20 ± 2 year; height: 171 ± 14 cm; weight: 63.5 ± 9.1 kg) participated in this randomized, double-blind, placebo-controlled cross-over study. Bayesian statistical methods were utilized, and parameter estimates were interpreted as statistically significant if the 95% highest-density intervals (HDIs) did not include zero. TTF was increased in the MIPS condition with a posterior Mean = 154 ± 4.2 s (95% HDI: -167, 465) and a 0.84 posterior probability that the supplement would increase TTF relative to PL. Blood lactate concentration immediately post-exercise was also higher in the MIPS condition compared to PL with an estimated posterior Mean = 3.99 ± 2.1 mmol (95% HDI: -0.16, 7.68). There were no differences in HR or RPE between trials. These findings suggest that a MIPS ingested prior to sustained running at lactate threshold has an 84% chance of increasing TTF in highly trained runners and may allow athletes to handle a higher level of circulating lactate before reaching exhaustion.
本研究旨在确定一种多成分的运动前补剂（MIPS）对长跑至力竭状态下的心率（HR）、主观疲劳感（RPE）、血乳酸浓度和疲劳时间（TTF）的影响。11 名美国大学生体育协会（NCAA）一级越野跑运动员（20±2 岁；身高：171±14cm；体重：63.5±9.1kg）参与了这项随机、双盲、安慰剂对照交叉研究。采用贝叶斯统计方法，若 95%最高密度区间（HDI）不包含零，则参数估计被解释为具有统计学意义。MIPS 组的 TTF 增加，后验均值=154±4.2s（95%HDI：-167，465），且补充剂相对于 PL 增加 TTF 的后验概率为 0.84。与 PL 相比，MIPS 组运动后即刻的血乳酸浓度更高，估计后验均值=3.99±2.1mmol（95%HDI：-0.16，7.68）。试验之间 HR 和 RPE 没有差异。这些发现表明，在乳酸阈下进行持续长跑前摄入 MIPS，有 84%的可能性会增加高训练水平跑者的 TTF，并可能使运动员在达到疲劳前能够处理更高水平的循环乳酸。
