Analysis of nonlinear and linear behaviors of heart rate for running exercise

This study investigates the nonlinear/linear behaviors of human heart rate response to treadmill exercise, for young and healthy subjects. The heart rate of the subject is measured, starting at a speed of 7 km/h, and increasing until the maximum heart rate for the subject is reached. The obtained nonlinear model is complicated and is not robust. Furthermore, sustained exercise at maximum heart rate is not always safe. For these reasons, this is not a suitable method for running exercise. Instead, we develop simple linear models for the same speed range, which is suitable for treadmill running exercise. We also propose a new model, called dasiaH modelpsila, to predict the percentage of heart rate reserve during running exercise. It has been proven that the presented model can predict the percentage change of heart rate for running exercise in the identified linear response range.