THE RELATIVE COST OF CHILDRENS PHYSICAL PLAY

There has been a long-standing debate regarding the functions of play during childhood. An important, but neglected, first step in this deba te entails documenting the costs associated with play. In this study w e analysed energetic costs (expressed in terms of caloric expenditure) associated with physical play in four field experiments of play in pr imary schoolchildren. Experiment 1 established the concurrent validity of an observational check list to estimate caloric expenditure of chi ldren's physical play. Experiment 2 compared caloric expenditure of th e play (defined as all behaviour exhibited during play time) for two a ge groups of children during playtime outdoors and during indoor seden tary activity; caloric expenditure of outdoor activity was greater and was significantly correlated with ambient temperature. In experiment 3, children were observed, during indoor play to control for the influ ence of ambient temperature. Outdoor physical Flay was more energetica lly costly than indoor physical play. In experiment 4, children's beha viour was observed outdoors and caloric expenditure for play, games an d other activities was compared. Physical play was more costly than ot her forms of behaviour and games. Estimates of total energetic costs o f play ranged from 6 to 15%. Results are discussed in terms of the rel atively low caloric costs of play. (C) 1998 The Association for the St udy of Animal Behaviour.