Evaluation of Exercise Intensity by Real-time Skin Lactate Monitoring System

Abstract

A sweat lactic acid (LA) monitoring system embedded on an armband for evaluation of exercise intensity was fabricated and real-time LA monitoring of a free-moving subject was conducted for the first time. The LA monitoring system utilizes an electrochemical biosensor which uses redox reaction of lactate oxidase immobilized on a screen-printed carbon graphite electrode. The volunteer wearing the system on the upper arm performed bouldering activity (climbing and 2 min rest alternately) in two different difficulty levels (100 and 150 degrees). Different secretion of LA was confirmed (11µg/cm² /min for the 150 degrees course and 2µg/cm² /min for the 110 degrees course). This indicates that the LA levels obtained with our system successfully reflected the metabolic status of the subject.