Flexible and stretchable bioelectronics for sports wearable monitoring: Materials, Device Engineering, and...

Modern sports science is undergoing a paradigm shift from subjective coaching to objective, data-driven precision training. Consequently, wearable electronics for acquiring precise data during sports activities are attracting attention. However, conventional rigid wearables inherently suffer from mechanical mismatches between rigid wearables and the soft, deformable human skin, inducing severe motion artifacts and restricting natural biomechanics during high-intensity athletic activities. To address these limitations from a comprehensive perspective, this review systematically summarizes and analyzes recent advancements in next-generation flexible and stretchable bioelectronics tailored specifically for sports applications. We systematically examine the substrate materials, structural engineering designs, and device-level optimization strategies required to withstand repetitive strain, shear, and sweat-intensive environments. Building upon these conformable bio-interfaces, we discuss three core sensing modalities: electrochemical sensors for real-time analysis of sweat biomarkers, biophysical sensors for continuous electrophysiological and hemodynamic monitoring, and electromechanical sensors for high-fidelity kinematic and impact tracking. Furthermore, we discuss body-derived energy harvesting strategies to power sports wearables and wireless communication systems for continuous athletic monitoring. The importance of artificial intelligence and machine learning is increasing, as these techniques enable the removal of motion artifacts and facilitate objective analysis of athletic data for training and health monitoring applications. By evaluating targeted applications across aerobic and anaerobic exercise, cognitive state assessment, and post-exercise recovery, this review demonstrates how next-generation sports wearables contribute to the shift in sports science from reactive treatment toward proactive, data-driven performance enhancement and injury prevention.