AN ANALYSIS OF EXCESSIVE RUNNING IN THE DEVELOPMENT OF ACTIVITY ANOREXIA

Food restriction combined with activity wheel access produces activity anorexia: a combination of excessive running, reduced food intake and rapid weight loss. Temporal distributions of running in activity anor exia were examined in a reversal design with one of 2 x 2 x 2 factoria l combinations (pelleted-vs-powdered food x deprivation x wheel access ) as the treatment condition. Wheel revolutions were recorded in 30 mi n intervals; body weights, food and water intakes were measured daily. Only wheel access combined with food deprivation reliably produced ac tivity anorexia. Excessive running occurred in the absence of schedule -induced polydipsia, was unaffected by food form, and showed distribut ional characteristics of facultative behavior. These results are incon sistent with schedule-induced behavior explanations. Running distribut ions appeared consistent with chronobiological models with light/dark onset and feeding serving as zeitgebers.