Simulating heart rate kinetics during incremental and interval training

Summary Study aim: To apply a recently proposed dynamical systems model to simulate, for the first time, the heart rate (HR) response to exercise of time-dependent intensity. Material and methods: The applied model is expressed in the form of two coupled ordinary differential equations, one giving the rate of change of HR and the other providing the time dependency of exercise intensity. According to the model, the HR is assumed to depend on time, velocity, lactate accumulation and the subject’s overall cardiovascular condition. For the purposes of the present work, training sessions were simulated, consisting of exponentially and step-wise increasing intensities, as well as interval training. Results: Training sessions of exponentially and step-wise increasing velocity, as well as an interval training session, have been simulated. Successful simulations of the corresponding HR response were achieved. Conclusions: The present work successfully demonstrates the model’s excellent performance in simulating the HR response to exercises of time-dependent intensity. The applied model has been shown to correctly simulate the heart rate response also during exercises of complicated intensity patterns, such as the interval training session. The study confirms the ability of the implemented mathematical model not only to simulate and predict heart rate kinetics for any given exercise intensities but also to provide important information regarding an individual’s cardiovascular condition. This is of vast importance, not only in the area of fitness and sport, where it can serve as a fundamental tool for the design of efficient training sessions, but also in the areas of cardiovascular health, prediction and rehabilitation.