The Ergogenic Potential of Succinic Acid in Exercise Performance and Post-Exercise Recovery: A Systematic Review

<b>Background</b>: Succinic acid plays a central role in human energy metabolism as a key intermediate of the Krebs cycle that releases energy accumulated as guanosine triphosphate (GTP). Through its conversion via succinate dehydrogenase (SDH), succinate directly links the Krebs cycle to oxidative phosphorylation (OXPHOS), contributing to adenosine triphosphate (ATP) production. Exercise induces pronounced changes in succinate concentrations in skeletal muscle, blood, and saliva, with responses influenced by training status, exercise modality, and intensity. <b>Objective</b>: This systematic review evaluated the effects of succinate-containing supplements or sole-ingredient succinic acid supplementation on exercise performance and post-exercise recovery in healthy trained individuals. <b>Methods</b>: The review was conducted in accordance with PRISMA guidelines. PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar were searched without date restrictions. Interventional studies assessing succinate-containing supplementation with outcomes related to exercise performance or recovery were included. Methodological quality was evaluated using the Cochrane Risk of Bias 2 tool. This study was registered in advance with the International Prospective Register of Systematic Reviews (<b>PROSPERO, CRD420251237042</b>). <b>Results</b>: Six studies involving 153 participants (mean age: 23 years) met the inclusion criteria. Five of the six included studies were rated as having a high risk of bias, while the only study judged to be at low risk of bias reported no beneficial effects on exercise performance outcomes. Supplementation protocols included daily doses of 300-2040 mg for up to 21 days and a single acute dose of 30 mg/kg, with most interventions administering succinate as part of multi-ingredient formulations rather than as an isolated compound. Three studies reported ergogenic effects in direct performance metrics, including improvements in maximal oxygen uptake, oxygen consumption, anaerobic threshold power, and total work performed. Two additional studies demonstrated favorable physiological adaptations indirectly relevant to exercise performance, including improved acid-base regulation, hematological markers related to oxygen transport, and antioxidant status, although validated performance outcomes were not assessed. Substantial heterogeneity and overall methodological limitations precluded meta-analysis. <b>Conclusions</b>: Current evidence suggests that succinate-containing supplements or sole-ingredient succinic acid supplementation may enhance direct performance outcomes such as aerobic performance, total workload, and indirect physiological markers, e.g., acid-base balance, hematological indicators and antioxidant capacity in healthy trained individuals. However, given that the majority of included studies were at high risk of bias and the only low-risk study reported no ergogenic effects, current evidence does not provide reliable support for performance-enhancing benefits of succinate supplementation. Interpretation is further limited by the predominant use of multi-ingredient formulations, making it difficult to isolate the effects of succinic acid. While biologically plausible mechanisms exist, well-controlled trials using isolated succinic acid are required before conclusions regarding efficacy can be drawn.