An experimental feasibility study evaluating the adequacy of sportswear-type wearables for recording physical exercise intensity

Abstract

Sportswear-type wearables with integrated inertial sensors and electrocardiogram (ECG) electrodes, have been developed. We examined the feasibility of using sportswear-type wearables to evaluate exercise intensity within a controlled laboratory setting. Six male college athletes were asked to don a sportswear-type wearable while performing a treadmill test that reached up to 20 km/h. The magnitude of the filtered tri-axial acceleration signal, recorded by the inertial sensor, was used to calculate the acceleration index. The R-R intervals of ECG were used to determine heart rate; the external validity of the heart rate was then evaluated according to oxygen uptake, which is the gold standard physiological exercise intensity. Single regression analyses between treadmill speed and the acceleration index in each participant showed that the slope of the regression line was significantly greater than zero with a high coefficient of determination (walking, 0.95; jogging, 0.96; running, 0.90). Another single regression analyses between heart rate and oxygen uptake showed that the slope of the regression line was significantly greater than zero, with a high coefficient of determination (0.96). Together, these results indicate that sportswear-type wearables are a feasible technology for evaluating physical and physiological exercise intensity across a wide range of physical activities and sport performances.