CAFFEINE AND SODIUM BICARBONATE SUPPLEMENTATION IN SPORT: MECHANISMS, PERFORMANCE EFFECTS, AND INTER-INDIVIDUAL VARIABILITY – A LITERATURE REVIEW
DOI:
https://doi.org/10.31435/ijitss.1(49).2026.5083Keywords:
Caffeine, Sodium Bicarbonate, Ergogenic Aids, Buffering Capacity, Exercise Performance, Metabolic AcidosisAbstract
Background: Caffeine and sodium bicarbonate are among the most extensively investigated ergogenic aids in sport. Although both supplements independently demonstrate performance-enhancing properties, uncertainty remains regarding their combined efficacy and the magnitude of inter-individual variability in response.
Aim: The purpose of this literature review was to critically synthesize contemporary evidence regarding (1) physiological mechanisms underlying caffeine and sodium bicarbonate supplementation, (2) independent performance outcomes across exercise modalities, (3) combined supplementation strategies, and (4) determinants of inter-individual responsiveness.
Material and methods: A structured narrative review was conducted using PubMed, Scopus, Web of Science, and SPORTDiscus. Twenty-three peer-reviewed human studies were included, comprising randomized controlled trials, systematic reviews, meta-analyses, and international position stands. Evidence was synthesized thematically.
Results: Caffeine consistently improves endurance, intermittent, and strength performance primarily via central adenosine receptor antagonism and reduced perception of effort. Sodium bicarbonate enhances high-intensity exercise capacity by increasing extracellular buffering capacity and facilitating proton efflux. However, additive ergogenic effects during combined supplementation are not consistently supported. Inter-individual variability is influenced by genetic polymorphisms (CYP1A2), habitual intake, gastrointestinal tolerance, training status, and nutritional context.
Conclusions: Caffeine and sodium bicarbonate independently demonstrate ergogenic potential under specific physiological conditions. Current evidence does not justify universal combined supplementation. Individualized protocols remain essential.
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Copyright (c) 2026 Daniel Markowski, Jakub Rodziewicz, Wiktor Daniszewski, Viktoria Kretschmer, Magdalena Baranowska, Ewa Sobolewska, Patryk Kondracki, Marcin Markowski
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