A comprehensive review of the physiology and evidence base to guide the use of ergogenic and medical supplements for enhanced cycling performance.

Abstract

A growing body of evidence supports the use of supplements to enhance cycling performance through both direct and indirect mechanisms. This review was informed by a structured literature search conducted in PubMed, Scopus and Web of Science for peer-reviewed studies published up to May 2025. Studies were included if they involved human participants, were published in English and evaluated outcomes related to endurance performance, recovery or physiological function. Direct enhancement with ergogenic supplements is primarily achieved via modulation of skeletal muscle energy metabolism. During exercise, adenosine triphosphate (ATP) resynthesis is driven by the phosphagen system, glycolysis, oxidative phosphorylation and beta-oxidation, with each system contributing according to the intensity and duration of the effort. Supplements such as beta-alanine, caffeine, carbohydrates, carnitine, creatine monohydrate, dietary nitrates, electrolytes, exogenous ketones, N-acetylcysteine and sodium bicarbonate support these energy systems by improving substrate utilization, buffering capacity, energy availability or resistance to fatigue. In addition to ergogenic supplements that directly enhance performance, medical supplements play an important indirect role by supporting bone health, connective tissue integrity, inflammation management, micronutrient status, muscle repair and gut function. Evidence-based options for cyclists include calcium, cherry juice, collagen, curcumin, iron, multivitamins, omega-3 fatty acids, pickle juice, probiotics, protein, vitamin C, vitamin D and zinc. Each contribute to either improved recovery, immune support or long-term physiological adaptation. Evidence quality varied substantially across supplements, with strongest support for Australian Institute of Sport (AIS) Group A compounds. The integration of physiological testing including assessments of maximal oxygen consumption (VO 2 max), lactate threshold, metabolic substrate utilization and blood biomarkers may inform the development of individualized supplementation strategies tailored to training demands and competitive goals. This evidence-informed approach underscores the synergistic relationship between nutrition, training and performance optimization in cycling. Future research should explore personalized nutrition frameworks, interactions between multi-supplement protocols and the molecular mechanisms underpinning adaptation to endurance training and nutritional interventions.