Effect of Caffeine and Nitrates Combination on Exercise Performance, Heart Rate and Oxygen Uptake: A Systematic Review and Meta-Analysis
Background: The evidence about the synergy of combining caffeine (CAF) and nitrates on exercise performance has not been summarized, although there is a possibility of additive/synergistic effects of the co-ingestion of these substances given their different mechanisms of action in central (CAF) and...
| Authors: | , , , |
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| Format: | article |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | Universidad Autónoma de Madrid |
| Repository: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Language: | English |
| OAI Identifier: | oai:repositorio.uam.es:10486/720597 |
| Online Access: | http://hdl.handle.net/10486/720597 https://dx.doi.org/10.3390/nu16193352 |
| Access Level: | Open access |
| Keyword: | beetroot juice caffeine co-supplementation nitrates performance Deportes |
| Summary: | Background: The evidence about the synergy of combining caffeine (CAF) and nitrates on exercise performance has not been summarized, although there is a possibility of additive/synergistic effects of the co-ingestion of these substances given their different mechanisms of action in central (CAF) and peripheral tissues (nitrates). Objectives: The aim was to analyze the effects of co-supplementation of CAF and nitrates on sports performance in comparison to the isolated ingestion of these substances. Methods: The databases of PubMed, Web of Science, Medline, CiNAHL and SPORTDiscus were used until June 2024 following PRISMA guidelines. Randomized controlled trials, at least one single-blind trial, conducted in adults were considered. A meta-analysis was performed using the random effects model to calculate the standardized mean difference estimated by Hedges’ g and 95% confidence intervals (CIs) for studies with four arms. Results: Six studies were included (N = 95). The meta-analysis revealed that caffeine and nitrates supplementation (CAF+nitrates) did not enhance performance in time trials (TTs) over the CAF alone (g = −0.06; 95% CI = −0.46 to 0.35; p = 0.78) or nitrates alone (g = 0.29; 95% CI = −0.12 to 0.70; p = 0.17). CAF+nitrates did not affect heart rate during submaximal exercise trials over CAF alone (g = 0.04; 95% CI = −0.31 to 0.40; p = 0.80) or nitrates alone (g = −0.15; 95% CI = −0.50 to 0.20; p = 0.40). Likewise, CAF+nitrates did not affect oxygen uptake during submaximal exercise trials over CAF alone (g = −0.04; 95% CI = −0.45 to 0.37; p = 0.84) or nitrates alone (g = −0.29; 95% CI = −0.70 to 0.12; p = 0.16). Conclusions: CAF+nitrates did not offer further benefits on exercise performance or physiological variables from the isolated intake of CAF and nitrates. |
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