Haynes James T, Townsend Jeremy R, Aziz Marko A, Jones Megan D, Littlefield Laurel A, Ruiz Matthew D, Johnson Kent D, Gonzalez Adam M
Exercise and Nutrition Science Graduate Program, Lipscomb University, Nashville, TN 37204, USA.
Department of Health Professions, Hofstra University, Hempstead, NY 11549, USA.
Sports (Basel). 2021 May 27;9(6):77. doi: 10.3390/sports9060077.
The purpose of this study was to assess the impact of short-term dietary nitrate supplementation, in the form of red spinach extract (RSE), on bench press performance, muscle oxygenation, and cognitive function in resistance-trained males. Ten resistance-trained males participated in this randomized, cross-over, placebo-controlled, double-blind investigation. Each participant completed 7 days of either RSE (2 g; 180 mg NO) or a maltodextrin placebo (PL) in a counterbalanced fashion with a 14-day washout between treatments. During experimental visits, participants were provided their 8th and last dose of RSE or PL 40 min before completing 5 sets of the barbell bench press exercise to failure at 75% of a predetermined 1-repetition maximum with 2 min rest intervals. Mean and peak power were recorded via a linear transducer. Near-infrared spectroscopy (NIRS) was implemented to estimate muscle oxygenation, a Stroop Test was used to assess cognitive function, and subjective performance ratings were obtained in relation to the acute resistance exercise sessions. Data were analyzed via separate repeated measures analyses of variance. There were no time by group interactions for bench press repetitions ( = 0.549), peak power ( = 0.061), or mean power ( = 0.877) across the 5 sets of bench press. Additionally, no significant differences ( > 0.05) were observed for any measure of muscle oxygenation, Stroop performance, or subjective performance ratings. It appears that 7 days of RSE supplementation did not alter performance, muscle oxygenation, nor Stroop scores during or following the bench press exercise in resistance-trained males.
本研究的目的是评估以红菠菜提取物（RSE）形式进行的短期膳食硝酸盐补充对阻力训练男性的卧推表现、肌肉氧合和认知功能的影响。十名阻力训练男性参与了这项随机、交叉、安慰剂对照、双盲调查。每位参与者以平衡的方式完成7天的RSE（2克；180毫克硝酸盐）或麦芽糊精安慰剂（PL），治疗之间有14天的洗脱期。在实验访视期间，参与者在以预定的1次重复最大值的75%完成5组杠铃卧推运动至力竭前40分钟，接受第8次也是最后一次剂量的RSE或PL，每组之间休息2分钟。通过线性传感器记录平均功率和峰值功率。采用近红外光谱（NIRS）估计肌肉氧合，使用Stroop测试评估认知功能，并获取与急性阻力训练相关的主观表现评分。通过单独的重复测量方差分析对数据进行分析。在5组卧推中，卧推重复次数（ = 0.549）、峰值功率（ = 0.061）或平均功率（ = 0.877）在组间没有时间交互作用。此外，在肌肉氧合、Stroop表现或主观表现评分的任何测量中均未观察到显著差异（ > 0.05）。看来，在阻力训练男性中，补充7天的RSE在卧推运动期间或之后并未改变表现、肌肉氧合或Stroop得分。
