Relationship between maximal aerobic power with aerobic fitness as a function of signal-to-noise ratio.

Efforts to better understand cardiorespiratory health are relevant for the future development of optimized physical activity programs. We aimed to explore the impact of the signal quality on the expected associations between the ability of the aerobic system in supplying energy as fast as possible during moderate exercise transitions with its maximum capacity to supply energy during maximal exertion. It was hypothesized that a slower aerobic system response during moderate exercise transitions is associated with a lower maximal aerobic power; however, this relationship relies on the quality of the oxygen uptake data set.

A phenomenology model of normal sinus rhythm in healthy humans.

The fractal component in the daytime healthy heartbeat interval data is studied from the perspective of cascade in fluid turbulence. Based on the electrophysiology of the heart muscle cell, a bounded random cascade model is assumed and the scaling property of the model is derived. In application, a "cascade decomposition" is proposed to extract the model parameter based on the experimental data.