During exercise, the locomotor and the cardiovascular system work in synergy to control the blood flow through the body. In particular, the muscle contraction generates rhythmic raising and lowering of intramuscular pressure, which in synergy supports cardiovascular function. This study aims to analyze spontaneous cardiac-locomotor coupling (CLC) events during daily activities using weareable sensors.

We analyze the dataset PMData, containing recordings from sixteen healthy subjects during five months. The data were acquired with a smartwatch and consist of step rate (SR), heart rate (HR) and daily surveys reporting the training sessions. Coupling is defined as being present when SR and HR are within 1% of each other (strong coupling) and within the 10% of each other (weak coupling).

The results show that every subject presents occurrences of CLC while performing normal daily activities. In particular, strong coupling occurs more likely for longer activities (111 ± 34 min), at moderate intensity (100 steps/min < SR > 130 steps/min).

The presence of CLC during daily activities rises the question whether there is a physiological mechanism controlling this phenomenon, that should be investigated in future.