(Poly)phenols and exercise: mechanisms and supplement evidence
الفلافونويدات والأداء: آليات الدليل وتأثير المكملات
Journal: Experimental physiology
University: Experimental Physiology (journal); authors' affiliations not specified in abstract
Study Type: review
Evidence Level: moderate
Published:
30-Second Summary
This is a contemporary review of (poly)phenols focusing on mechanisms and evidence for exercise recovery and performance. The authors emphasize that (poly)phenols likely work via signalling pathways (e.g., Nrf2) to upregulate endogenous antioxidant defenses rather than acting as direct in vivo antioxidants, and they note mixed but potentially modest benefits of supplements.
1-Minute Summary
The review synthesizes current mechanistic and applied evidence on (poly)phenols for exercise recovery and performance. It highlights that many reported benefits attributed to antioxidant action are unlikely to be due to direct free-radical scavenging in vivo; instead, (poly)phenols may modulate redox balance by activating transcriptional pathways such as Nrf2 and other signalling networks. The authors summarize human and animal data showing variable effects on inflammation, muscle damage markers, and performance outcomes, with heterogeneity by compound, dose, timing and formulation. They caution about inconsistent results, potential interactions with training adaptations, and the need for more rigorous, well-characterized human trials.
3-Minute Summary
This review examines the biology and evidence for (poly)phenol supplements as aids for exercise recovery and performance. (Poly)phenols, a chemically diverse group found in many plant foods, have long been attributed antioxidant, anti-inflammatory and vasodilatory properties. The authors argue that direct antioxidant activity in vivo is unlikely because of low bioavailability and rapid metabolism; instead, (poly)phenols appear to act via signalling pathways — notably activation of the transcription factor Nrf2 — that upregulate endogenous antioxidant defences, and by modulating inflammation and nitric-oxide–related vascular responses. Human and animal studies provide mixed, generally modest, benefits on markers such as creatine kinase, inflammatory cytokines, delayed-onset muscle soreness and some performance metrics. Effects vary strongly with the specific compound (e.g., quercetin, resveratrol, tart cherry, curcumin), dose, formulation, timing relative to exercise, and participant characteristics (trained vs untrained). Many positive findings stem from animal or small human trials; larger, well-controlled human randomized trials with standardized dosing, pharmacokinetic profiling and attention to metabolites and the gut microbiome are needed. Overall, the review suggests mechanistic plausibility for signalling-mediated effects and indicates that selected (poly)phenol-rich preparations may modestly support recovery or performance in some contexts, but evidence is heterogeneous and not definitive.
Full Analysis
Mechanisms: The review emphasizes that most reported benefits of (poly)phenols are unlikely to arise from direct radical-scavenging in vivo because oral doses produce low systemic concentrations, extensive phase I/II metabolism, and rapid conjugation. Instead, bioactive parent compounds and, importantly, gut- and host-derived metabolites appear to modulate intracellular signalling networks. Activation of Nrf2 is highlighted as a central mechanism: modest electrophilic or redox interactions with Keap1 can release Nrf2, increasing expression of endogenous antioxidant enzymes (e.g., glutathione-related enzymes, heme oxygenase-1). Parallel anti-inflammatory effects are attributed to modulation of NF-κB and cytokine signalling. Vascular effects (improved endothelial function, NO bioavailability) may also contribute to perfusion and recovery but show variable translation to functional outcomes. Pharmacokinetics and the gut microbiome: interindividual differences in metabolism and microbial biotransformation produce heterogeneous metabolites with distinct bioactivities; this variability likely explains inconsistent trial results. Evidence base: animal models frequently report protection against oxidative markers, muscle damage and inflammation; human trials yield mixed, generally modest effects on markers (CK, IL-6, CRP), subjective soreness and some performance measures. Heterogeneity stems from differing polyphenol classes, doses (dietary vs supplemental, low vs pharmacological), formulations (enhanced bioavailability), timing (pre-, peri-, post-exercise), participant training status, and small sample sizes. Methodological gaps: many human studies lack robust randomization, blinding, standardized outcome measures, or pharmacokinetic/metabolite profiling. Safety and training adaptations: limited data suggest potential for interaction with training-induced signalling (e.g., redox-mediated mitochondrial adaptations), so chronic high-dose use merits caution and targeted study. Recommendations: future work should prioritize well-powered RCTs with standardized preparations, time-course biomarker panels, metabolite and microbiome analyses, and functional performance endpoints to clarify which compounds, doses and contexts most plausibly support recovery or performance.Health Implications
Practical daily habits that may support beneficial (poly)phenol actions: favor a varied, plant-rich diet (berries, cherries, citrus, tea, cocoa, turmeric, leafy greens) rather than relying solely on isolated supplements; include whole fruits, vegetables and legumes to supply both (poly)phenols and dietary fiber, which encourages microbiome-mediated metabolism; choose minimally processed foods to preserve phytochemicals. If using supplements, prefer standardized preparations with known doses and timing, and avoid very high chronic doses without professional guidance. Pairing polyphenol-rich meals with consistent training, adequate protein and sleep supports recovery broadly. Consult sports nutrition or healthcare professionals to align strategies with personal goals and safety; evidence suggests these approaches may support recovery and health but is not definitive.
Key Findings
- (Poly)phenols are unlikely to act as direct antioxidants in vivo; their effects are more plausibly mediated via signalling pathways (e.g., Nrf2) that upregulate endogenous antioxidant systems.
- Human and animal studies show mixed evidence for modest benefits of (poly)phenol supplements on inflammation, muscle damage markers and performance; outcomes vary with compound, dose, timing and formulation, and more rigorous human trials are needed.
DOI: 10.1113/EP093724