Modern soccer combines intermittent high-intensity actions with sustained aerobic work, imposing substantial metabolic demand on players. This combined demand contributes to increased production of reactive oxygen species and oxidative stress, perturbations in energy systems, and impairment of post-exercise recovery processes. The reviewed literature examines whether multi-target nutritional supplements can meaningfully support match and training performance and accelerate recovery in soccer players. The review specifically synthesizes evidence for melatonin, gut-axis interventions (prebiotics, probiotics, and synbiotics), magnesium, sodium pyruvate, and purple grape-derived products, with attention to mechanistic links between supplementation and applied performance or biochemical outcomes.
Twenty-two interventional studies conducted in soccer players were systematically identified and qualitatively synthesized following PRISMA 2020 reporting guidance. Risk of bias and methodological quality were assessed using design-appropriate tools: the Cochrane Risk of Bias 2 (RoB 2) tool for randomized controlled trials and the ROBINS-I framework for non-randomized intervention studies. An adapted GRADE framework was used to evaluate overall certainty of evidence. The synthesis prioritized study design features, dosing and timing protocols, measured performance and biochemical outcomes, and methodological limitations, with an emphasis on linking mechanistic evidence to practical performance and recovery endpoints.
Across the included trials, melatonin was administered either nocturnally or shortly before exercise. Mechanistic findings consistently indicated reductions in markers of oxidative damage and upregulation of endogenous antioxidant enzymes following melatonin supplementation. These biochemical effects were associated in several studies with attenuation of short-term declines in performance after stress or exercise. However, effects on maximal performance indices were inconsistent across trials, with some studies showing limited or no benefit for peak power or maximal aerobic capacity. The review highlights mechanistic plausibility—antioxidant and anti-inflammatory actions—but notes heterogeneity in dosing, timing, and measured endpoints that complicates cross-study comparison.
Interventions targeting the gut axis, including prebiotics, probiotics, and synbiotics, produced several consistent findings in the pooled interventional evidence. These products enhanced mucosal immunity measures and reduced the incidence and duration of upper respiratory tract infections (URTI) in soccer players. They also decreased reports of delayed onset muscle soreness (DOMS) in multiple studies. Certain combined formulations—especially those co-administered with protein or spirulina—demonstrated additional benefits on body composition and measures of muscular strength. Mechanistically, benefits were linked to modulation of gut microbiota, immune function, and possibly systemic inflammatory status, but the review notes variability in strains, doses, and intervention durations across studies.
Supplementation with magnesium alone showed limited and inconsistent benefits among athletes who were not magnesium-deficient. The trials reviewed did not uniformly demonstrate performance enhancements from magnesium monotherapy. However, when magnesium was included in combined formulations, some studies reported potential improvements in buffering capacity and anaerobic performance metrics. The summary emphasizes that benefits may be context-dependent—more likely in individuals with baseline deficiency or when magnesium is part of a multi-ingredient strategy—while remaining cautious about generalizing effects to all soccer players.
Short-term sodium pyruvate supplementation was reported to support resynthesis of the ATP-PCr energy system and to enhance repeated sprint performance in the included studies. Mechanistic rationale rests on pyruvate’s role in cellular energy metabolism and its potential to influence bioenergetic recovery between high-intensity efforts. The review indicates positive findings for repeated-sprint outcomes but acknowledges that protocols were short-term and that sample sizes were small.
Products derived from purple grapes increased serum antioxidant capacity in the participant groups studied. In some participants, these antioxidant changes were accompanied by improvements in endurance performance measures. The mechanistic link proposed is augmentation of systemic antioxidant defenses, which could attenuate oxidative damage and preserve performance under sustained aerobic or intermittent high-intensity loads. As with other interventions, heterogeneity in formulation, dose, and outcome measurement limits strong, generalized conclusions.
Key limitations across the 22 interventional studies included small sample sizes, heterogeneity of supplementation protocols (dosing, timing, and composition), and a lack of standardized mechanistic biomarkers that would facilitate cross-study comparison and mechanistic inference. The overall certainty of evidence, as appraised with an adapted GRADE approach, was therefore constrained. The reviewed supplements—melatonin, gut-axis therapies, magnesium (particularly in combinations), sodium pyruvate, and purple grape-derived products—may offer mechanistically plausible support for performance and recovery in soccer players. Nonetheless, the authors conclude that larger-scale, field-based randomized controlled trials with standardized biomarker panels and consistent outcome measures are required to establish precise, evidence-based operational strategies for practitioners and athletes.