Allied Health and Human Performance, University of South Australia, Adelaide, Australia. Noah.D'
Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, Adelaide, Australia. Noah.D'
J Int Soc Sports Nutr. 2021 Dec 29;18(1):76. doi: 10.1186/s12970-021-00472-y.
Increasing nitric oxide bioavailability may induce physiological effects that enhance endurance exercise performance. This review sought to evaluate the performance effects of consuming foods containing compounds that may promote nitric oxide bioavailability.
Scopus, Web of Science, Ovid Medline, EMBASE and SportDiscus were searched, with included studies assessing endurance performance following consumption of foods containing nitrate, L-arginine, L-citrulline or polyphenols. Random effects meta-analysis was conducted, with subgroup analyses performed based on food sources, sex, fitness, performance test type and supplementation protocol (e.g. duration).
One hundred and eighteen studies were included in the meta-analysis, which encompassed 59 polyphenol studies, 56 nitrate studies and three L-citrulline studies. No effect on exercise performance following consumption of foods rich in L-citrulline was identified (SMD=-0.03, p=0.24). Trivial but significant benefits were demonstrated for consumption of nitrate and polyphenol-rich foods (SMD=0.15 and 0.17, respectively, p<0.001), including performance in time-trial, time-to-exhaustion and intermittent-type tests, and following both acute and multiple-day supplementation, but no effect of nitrate or polyphenol consumption was found in females. Among nitrate-rich foods, beneficial effects were seen for beetroot, but not red spinach or Swiss chard and rhubarb. For polyphenol-rich foods, benefits were found for grape, (nitrate-depleted) beetroot, French maritime pine, Montmorency cherry and pomegranate, while no significant effects were evident for New Zealand blackcurrant, cocoa, ginseng, green tea or raisins. Considerable heterogeneity between polyphenol studies may reflect food-specific effects or differences in study designs and subject characteristics. Well-trained males (V̇O ≥65 ml.kg.min) exhibited small, significant benefits following polyphenol, but not nitrate consumption.
Foods rich in polyphenols and nitrate provide trivial benefits for endurance exercise performance, although these effects may be food dependent. Highly trained endurance athletes do not appear to benefit from consuming nitrate-rich foods but may benefit from polyphenol consumption. Further research into food sources, dosage and supplementation duration to optimise the ergogenic response to polyphenol consumption is warranted. Further studies should evaluate whether differential sex-based responses to nitrate and polyphenol consumption are attributable to physiological differences or sample size limitations.
The review protocol was registered on the Open Science Framework ( https://osf.io/u7nsj ) and no funding was provided.
增加一氧化氮的生物利用度可能会产生增强耐力运动表现的生理效应。本综述旨在评估摄入可能促进一氧化氮生物利用度的化合物的食物对运动表现的影响。
检索 Scopus、Web of Science、Ovid Medline、EMBASE 和 SportDiscus，纳入评估摄入硝酸盐、精氨酸、瓜氨酸或多酚食物后耐力表现的研究。进行随机效应荟萃分析，并根据食物来源、性别、健康状况、性能测试类型和补充方案（例如持续时间）进行亚组分析。
荟萃分析纳入了 118 项研究，其中包括 59 项多酚研究、56 项硝酸盐研究和 3 项瓜氨酸研究。摄入富含瓜氨酸的食物对运动表现没有影响（SMD=-0.03，p=0.24）。摄入富含硝酸盐和多酚的食物可带来微不足道但有显著意义的益处（SMD 分别为 0.15 和 0.17，p<0.001），包括计时赛、力竭时间和间歇性测试中的表现，以及急性和多日补充后，而女性摄入硝酸盐或多酚没有效果。在富含硝酸盐的食物中，甜菜根有益，而红菠菜、瑞士菠菜和大黄则不然。对于富含多酚的食物，葡萄、（硝酸盐耗尽的）甜菜根、法国滨海松、蒙莫朗西樱桃和石榴有益，而新西兰黑加仑、可可、人参、绿茶或葡萄干则没有明显效果。多酚研究之间存在很大的异质性，这可能反映了食物特异性效应或研究设计和受试者特征的差异。经过良好训练的男性（V̇O≥65 ml.kg.min）在摄入多酚后表现出微不足道但显著的益处，但摄入硝酸盐则不然。
富含多酚和硝酸盐的食物对耐力运动表现有微不足道的益处，但这些益处可能取决于食物种类。高训练水平的耐力运动员似乎从摄入富含硝酸盐的食物中获益，但可能从摄入多酚中获益。需要进一步研究食物来源、剂量和补充持续时间，以优化对多酚摄入的促进作用。应该进一步研究是否对硝酸盐和多酚摄入的基于性别的不同反应归因于生理差异或样本量限制。
该综述方案已在开放科学框架（https://osf.io/u7nsj）上注册，没有提供资金。
