a Physical Education College, Zhengzhou University of Science and Technology,

Zhengzhou, Henan, 450064, China

b School of Physical Education, Hubei University of Science and Technology,

Hubei Xianning, 437100, China

This study presents the development of a flexible ZnO-Ecoflex composite sensor for non- invasive lactate detection during physical training. ZnO nanostructures with an average diameter of 50 nm were synthesized and incorporated into an Ecoflex matrix. The optimized sensor, featuring 15 wt% ZnO loading, demonstrated high sensitivity (22.7 μA·mM_ ¹ ·cm_²) and a low detection limit (2.3 μM). The composite displayed impressive mechanical characteristics, showcasing a tensile strength of 1.3 MPa and an elongation at fracture of 390%. Electrochemical characterization revealed a diffusion-controlled electron transfer process and rapid response time of 5 seconds. The sensor showed minimal interference from common sweat components (<3.2% relative response) and maintained consistent performance under various bending conditions (RSD 3.2%). Real-time monitoring during a 30-minute jogging session demonstrated the sensor's ability to capture dynamic changes in sweat lactate levels. This research contributes to the development of wearable biosensors for continuous lactate monitoring in sports and exercise science, offering potential for personalized training optimization.