Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA.
Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA.
J Diet Suppl. 2020;17(6):698-717. doi: 10.1080/19390211.2019.1650866. Epub 2019 Aug 28.
The ergogenic effects of citrulline malate (CitMal) and beetroot juice (BEET) have been widely studied, but their effects on physiological outcomes related to resistance exercise are not fully understood. The purpose of this randomized, double-blind, crossover study was to investigate the effects of CitMal (8 g) and BEET (400 mg nitrate) on blood pressure (BP), blood flow, and energy efficiency during submaximal leg extension. Recreationally active males ( = 27; age: 22 ± 4 yrs) completed familiarization, followed by three testing visits. Supine and standing BP were measured upon arrival, followed by supplement ingestion, a 2-h rest period, postsupplement BP measurement, and a bout of repeated submaximal isotonic leg extensions at 25% of maximal voluntary contraction torque. Diameter (aDIAM) and blood flow (aBF) of the superficial femoral artery, and cross-sectional area (CSA) and echo intensity (EI) of the vastus lateralis, were measured before and after exercise via ultrasonography. Muscle blood flow (mBF) and oxygen consumption (mVO), along with whole-body energy expenditure (EE) and respiratory exchange ratio (RER), were measured before and during exercise via indirect calorimetry and near-infrared spectroscopy. Baseline RER values differed among treatments ( = 0.01); BEET was higher than CitMal ( = 0.01) but not PLA ( = 0.58); CitMal and PLA were not significantly different ( = 0.12). No other measurements were significantly affected by treatment (all > 0.05). Results suggest that neither CitMal nor BEET significantly influence resting BP, blood flow, or metabolic efficiency during submaximal leg extension in recreationally active males.
瓜氨酸苹果酸盐（CitMal）和甜菜根汁（BEET）的促力作用已得到广泛研究，但它们对抗阻运动相关生理结果的影响尚不完全清楚。本随机、双盲、交叉研究的目的是探讨 CitMal（8g）和 BEET（400mg 硝酸盐）对次最大腿部伸展时血压（BP）、血流和能量效率的影响。有规律运动的男性（ = 27；年龄：22 ± 4 岁）完成了预适应，然后进行了三次测试访问。到达时测量仰卧位和站立位血压，随后摄入补充剂，休息 2 小时，测量补充后血压，以及在 25%最大自主收缩扭矩下进行反复次最大等长腿部伸展运动。通过超声测量股浅动脉直径（aDIAM）和血流（aBF），以及股外侧肌横截面积（CSA）和回声强度（EI）。通过间接测热法和近红外光谱法在运动前和运动期间测量肌肉血流（mBF）和耗氧量（mVO）以及全身能量消耗（EE）和呼吸交换率（RER）。处理之间的基线 RER 值存在差异（ = 0.01）；BEET 高于 CitMal（ = 0.01）但低于 PLA（ = 0.58）；CitMal 和 PLA 之间无显著差异（ = 0.12）。其他测量值均不受处理影响（均 > 0.05）。结果表明，在有规律运动的男性中，CitMal 或 BEET 均不会显著影响次最大腿部伸展时的静息血压、血流或代谢效率。
