[Assessment of reactivity of heart rhythm regulatory system in response to physical exertion].

The study involving 35 sportsmen and 35 non-sportsmen was undertaken to assess the reactivity of human heart sinus node in response to physical workload depending on the initial state of the blood circulation system. It is found that sportsmen have predominantly a hyperreactive type and non-sportsmen--a hyporeactive type of sinus node reactivity to workloads. Moreover, the reactivity of heart sinus node in response to physical workload depends considerably on the initial state of the system of blood circulation regulation at a relative rest. The regression equation for assessment of heart sinus node reactivity to workload is proposed.