Periodicity of changes in functional indices in animals and humans

We investigated the dynamics of food and water consumption, body weight gain, body density, body water content, and changes in the hypoxic endurance of rats. The analysis of primary data in the study of BRT in the activity of various human physiological systems made possible to establish an average value of the period of this biorhythm, which is 12.6 days. The synchronizer of this rhythm is unclear. However, its stability allows to speak of the presence of an external synchronizer, and, consequently, of the exogenous nature of the BRT and its adaptive role aimed at compensating for changes in environmental parameters.