Critical perspectives on electrochemical biosensing strategies for non-invasive lactate detection in athletic performance monitoring.

Abstract

Non-invasive monitoring of lactate levels offers a promising avenue for optimizing athletic performance assessment, yet remains constrained by the limitations of traditional blood-based sampling methods. This review critically examines electrochemical biosensing strategies for non-invasive lactate detection tailored to sports applications. Emphasis is placed on enzymatic, non-enzymatic, and molecularly imprinted polymer (MIP)-based approaches, each with distinct strengths and limitations in sensitivity, specificity, and operational stability. The suitability of various biofluids-sweat, saliva, and interstitial fluid (ISF)-is evaluated with regard to physiological relevance, correlation with blood lactate, and challenges in sampling and sensor integration. Particular attention is given to the physiological mechanisms governing lactate appearance in these fluids and their implications for real-time monitoring. Advanced materials such as nanostructured metal oxides, conductive polymers, and MOFs are discussed for their roles in enhancing electrocatalytic performance and biosensor durability. Despite significant advances, unresolved challenges persist, including weak or inconsistent correlation between biofluid and blood lactate, sensor biofouling, lag times in ISF detection, and insufficient validation in real-world athletic settings. The review highlights emerging strategies such as multiparametric sensing, machine learning models, and innovative sensor designs (e.g., microneedles, three-phase interfaces) as potential solutions to bridge these gaps. Future progress will depend on integrating physiological insight with materials innovation and rigorous validation to develop robust, field-deployable lactate biosensors that can transform athlete monitoring and training personalization.