Cardiolocomotor phase synchronization during rhythmic exercise

Biological rhythms can be entrained by internal oscillatory processes and often become synchronized with each other. For integrated physiological systems, there is evidence to show that coupling can exist between cardiorespiratory and locomotor systems. Phase synchronization, which has been well documented in articles describing cardiac and locomotor rhythms for individuals engaged in rhythmic activity such as walking, running, or cycling, is called “cardiolocomotor synchronization” or “cardiolocomotor coupling”. Although this coupling has been hypothesized to play a functional role during exercise, the nature of this interaction, its physiological relevance, and the underlying mechanism behind this phenomenon are not fully understood. This review summarizes research findings to date on cardiolocomotor synchronization, and aims to provide the method for identification of phase synchronization between cardiac and locomotor rhythms. In addition, the mechanisms responsible for the synchronization and possible physiological function of this interaction are discussed.