Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA ; Nutrabolt, Bryan, TX 77807 USA.
J Int Soc Sports Nutr. 2017 Jan 12;14:3. doi: 10.1186/s12970-016-0159-2. eCollection 2017.
The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety.
In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with (PWS + S) extract standardized for 30% -synephrine (20 mg). Participants had heart rate (HR), blood pressure, resting energy expenditure (REE), 12-lead electrocardiograms (ECG), perceptions about readiness to perform, cognitive function (Stroop Color-Word test), bench and leg press performance (2 sets of 10 repetitions at 70% of 1RM and 1 set to failure), and Wingate anaerobic capacity (WAC) sprint performance determined as well as donated blood samples prior to and/or following exercise/supplementation. Data were analyzed by MANOVA with repeated measures as well as mean changes from baseline with 95% confidence intervals (CI).
No clinically significant differences were observed among treatments in HR, blood pressure, ECG, or general clinical blood panels. There was evidence that PWS and PWS + S ingestion promoted greater changes in REE responses. Participants reported higher perception of optimism about performance and vigor and energy with PWS and PWS + S ingestion and there was evidence that PWS and PWS + S improved changes in cognitive function scores from baseline to a greater degree than PLA after 1 or 2 h. However, the scores in the PWS + S treatment did not exceed PLA or PWS responses at any data point. No statistically significant differences were observed among treatments in total bench press lifting volume, leg press lifting volume or WAC sprint performance.
Within the confines of this study, ingestion of PWS and/or PWS + S prior to exercise appears to be well-tolerated when consumed by young, healthy individuals. The primary effects appear to be to increase REE responses and improve perceptions about readiness to perform and cognitive function with limited to no effects on muscular endurance and WAC. The addition of 20 mg of -synephrine to the PWS provided limited to no additive benefits.
This trial (NCT02952014) was retrospectively registered on September 13th 2016.
本研究旨在考察急性摄入含或不含辛弗林（S）的运动前补充剂（PWS）对运动准备状态、认知功能、运动表现和安全性标志物的影响。
采用随机、双盲、交叉对照的方法；25 名健康且有规律进行体育锻炼的男性和女性参与者分别摄入调味麦芽糊精安慰剂（PLA）、含β-丙氨酸（3g）、硝酸肌氨酸盐（2g）、精氨酸α-酮戊二酸（2g）、N-乙酰-L-酪氨酸（300mg）、咖啡因（284mg）、标准化提取物 15%L-多巴（15mg）、维生素 C 抗坏血酸（500mg）、烟酰胺（60mg）、叶酸（50mg）和维生素 B12 甲钴铵（70mg）的 PWS 与 2g 麦芽糊精和调味剂；或 PWS 加（PWS+S）提取物标准化 30% -辛弗林（20mg）。参与者的心率（HR）、血压、静息能量消耗（REE）、12 导联心电图（ECG）、运动准备状态感知、认知功能（Stroop 颜色-单词测试）、卧推和腿推表现（2 组 10 次重复，70%的 1RM 和 1 组至力竭）以及 Wingate 无氧能力（WAC）冲刺表现以及运动/补充前后的血液样本进行了测定。采用重复测量的 MANOVA 分析数据，以及 95%置信区间（CI）的基线均值变化。
在 HR、血压、ECG 或一般临床血液指标方面，各组之间没有观察到临床显著差异。有证据表明，PWS 和 PWS+S 摄入可引起 REE 反应的更大变化。参与者报告说，服用 PWS 和 PWS+S 后，对运动表现和活力、能量的乐观感更高，有证据表明，与 PLA 相比，PWS 和 PWS+S 在 1 或 2 小时后对认知功能评分的改善更大。然而，在任何数据点，PWS+S 治疗的分数都没有超过 PLA 或 PWS 的反应。各组在总卧推举重量、腿推举重量或 WAC 冲刺表现方面没有观察到统计学上的显著差异。
在这项研究的范围内，年轻、健康的个体在运动前摄入 PWS 和/或 PWS+S 似乎可以耐受。主要影响似乎是增加 REE 反应，提高运动准备状态和认知功能的感知，对肌肉耐力和 WAC 的影响有限。在 PWS 中添加 20mg 的辛弗林对 PWS 没有提供额外的益处。
本试验（NCT02952014）于 2016 年 9 月 13 日进行了回顾性注册。
