Effect of dietary nitrate ingestion on muscular performance: a systematic review and meta-analysis of randomized controlled trials. Issue 19 (28th October 2022)

• Record Type: Journal Article
• Authors: Alvares, Thiago Silveira; Oliveira, Gustavo Vieira de; Volino-Souza, Mônica; Conte-Junior, Carlos Adam; Murias, Juan Manuel
• Is Part Of: Critical reviews in food science and nutrition. Volume 62:Issue 19(2022)
• Page Start: 5284
• Page End: 5306
• Publication Date: 2022-10-28
• Subjects: Functional foods -- vegetables -- beetroot -- sports nutrition -- exercise; Food industry and trade -- Periodicals; Nutrition -- Periodicals; Nutrition -- Periodicals; Food -- Periodicals; Diet -- Periodicals; Review Literature -- Periodicals; Nutrition; Food; Diet; Review Literature; 664
• DOI: 10.1080/10408398.2021.1884040
• Languages: English
• ISSNs: 1040-8398

Abstract

Abstract: Dietary nitrate consumption from foods such as beetroot has been associated with many physiological benefits including improvements in vascular health and exercise performance. More recently, attention has been given to the use of dietary nitrate as a nutritional strategy to optimize muscular performance during resistance exercise. Our purpose was to perform a systematic review and meta-analysis of the research literature assessing the effect of dietary nitrate ingestion on muscular strength and muscular endurance. A structured search was carried out in accordance with PRISMA guidelines and from the total included studies ( n = 34 studies), 12 studies had data for both measurement of strength and muscular endurance outcomes, 14 studies had data only for muscular strength outcome, and 8 studies had data only for muscular endurance outcome. Standardized mean difference (SMD) was calculated and meta-analyses were performed by using a random-effects model. Dietary nitrate ingestion was found to result in a trivial but significant effect on muscular strength (overall SMD = 0.08, P = 0.0240). Regarding muscular endurance dietary nitrate was found to promote a small but significant effect (overall SMD = 0.31, P < 0.0001). Dosage, frequency of ingestion, training level, muscle group, or type of contraction did not affect the findings, except for a greater improvement in muscle endurance during isometric and isotonic when compared to isokinetic contractions. Dietary nitrate seems to have a positive effect on muscular strength and muscular endurance, which is mostly unaffected by dosage, frequency of ingestion, training level, muscle group, or type of contraction. However, given the trivial to small effect, further experimental research on this topic is warranted.