Circadian System Heritability Assessed in Free Living Conditions

"Participation was completely voluntary and not remunerated. The subjects were organized into groups of 5 pairs, and were given an appointment at a university facility located in the city center, where informed consent was signed prior to the procedures indicated below. An informational letter was sent to pre-selected individuals. Later a phone call confirmed their availability.~* Temperature rhythm was assessed continuously for 7 days using a temperature sensor and programmed to collect information every 10 min.~* Body position and rest-activity rhythm were assessed over the same 7 days using a Acceleration Data Logger that record data every min and placed on the non-dominant arm by means of an elastic band, with its X axis parallel to the humerus bone.~* Diet and sleep record were completed over the same week, their sleep schedules and their nutritional status."