Wave-like reaction phenomena of the human body in head-down tilt

The biorhythmological analysis of the data obtained from 7 healthy male test subjects in the head-down position at -8 degrees revealed phenomena of sine-shaped reactions. This pattern was seen in the range (the difference between mean day-time and mean night-time values) of heart rate, amplitude (the difference between the maximum and minimum) of variations of body temperature and renal potassium excretion, and the evening-morning difference of body temperature variations.