CIRCADIAN-RHYTHMS OF BODY-TEMPERATURE AND URINARY-EXCRETION IN SUBJECTS ON 30-H DAYS

Eleven subjects, in groups of 2 or 3, have lived in an isolation unit for a period of 30-h ''days'' (10h sleep, 20h awake and sedentary). Re ctal temperature and urinary excretion of potassium and sodium were me asured throughout the experiment. Estimates of the phases of raw data indicated dissociation or desynchronization between the rhythms. When the data were ''purified'', however, the rhythms remained in phase wit h each other and showed a period in excess of 24h. The interpretive pr oblems produced by such a protocol are discussed.