Figure 8

Multiple-component serial section. Heart rate, self-measured a few times each day by a healthy man over several decades, was averaged over consecutive weeks. The weekly averages are fitted with a 3-component model consisting of cosine curves with periods of 1.0, 0.5, and 0.41 year in a 4-year interval moved by 0.2 year throughout the entire record. The time course of amplitudes of the 3 components is shown on top. Solid-filled, light-filled and empty symbols correspond to P-values <0.05, 0.05 < P < 0.10, and >0.10 from the zero-amplitude tests, respectively. Results for the 0.41-year component are reproduced below, where they are compared with the solar flare index that had been reported by physicists to be characterized by an about 5-month (0.41-year) component. The prominence of the about 5-month component in human heart rate follows an about 11-year cycle, which is similar to that characterizing solar flares. © Halberg Chronobiology Center.