Hindawi Publishing Corporation International Journal of Pediatrics Volume 2010, Article ID 218586, 6 pages doi:10.1155/2010/218586 Research Article Children’s Use of Electronic Games: Choices of Game Mode and Challenge Levels Cindy H. P. Sit, 1 Jessica W. K. Lam, 1 and Thomas L. McKenzie 2 1 Institute of Human Performance, The University of Hong Kong, Pokfulam, Hong Kong 2 School of Exercise and Nutritional Sciences, San Diego State University, 5500 Campanile Drive, CA 92182-7251, USA Correspondence should be addressed to Cindy H. P. Sit, sithp@hku.hk Received 16 January 2010; Accepted 1 June 2010 Academic Editor: Mutasim Abu-Hasan Copyright © 2010 Cindy H. P. Sit et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction. Interactive electronic games are popular and are believed to contribute to physical activity accrual. The purpose of this study was to examine children’s electronic game use during conditions in which they had free access to selecting interactive and seated screen-based versions of electronic games and during the interactive versions had free choice in making adjustments to the activity intensity. Methods. We systematically observed 60 Hong Kong primary school children during two 60-minute game sessions while simultaneously recording their game mode choices and physical activity levels using SOFIT (System for Observing Fitness Instruction Time). Results. When given free choice, children spent more than half of their available time participating in interactive versions of games. These versions of games provided significantly more moderate-to-vigorous physical activity and greater energy expenditure than the computer screen versions. Children with the opportunity to modify intensity levels spent more time playing the interactive versions and accrued more physical activity. Conclusions. The tenets of behavioral choice theory were supported. Access to new-generation interactive games, particularly those with modifiable intensity levels, may facilitate children’s participation in physical activity. 1. Introduction Current health guidelines recommended that children should participate in 60 minutes of moderate-to-vigorous physical activity (MVPA) daily [1]. Children, however, often adopt sedentary lifestyles and there is widespread concern that screen-based media such as computer and video games contribute to sedentary living and childhood obesity problems [2, 3]. New generation interactive electronic games, known as exergaming, have been developed and are considered as a promising way to promote physical activity in children. Previous studies have demonstrated that interactive electronic games can significantly increase physical activity in children [4–6], including eliciting greater energy expenditure compared to seated electronic games [7–12]. Boys are typically found to spend more energy during interactive games than girls [6, 7], but sometimes no significant gender effects are reported [8, 10]. Compared to overweight children, nonoverweight children have been shown to be more willing to play an interactive dance game [13]. These studies, however, have typically assessed children’s physical activity levels during short-time periods (e.g., 15 minutes per game segment), and without participants having a choice of the interactive or more sedentary computer screen-based versions of the same game. Direct observation exceeds other measures of physical activity in providing contextually-rich data on the envi- ronment [14, 15]. Several studies have used this method with cohorts of children in their homes in Hong Kong [16] and the USA [17, 18] and have shown that children spend most of their leisure time indoors and in sedentary pursuits. Using the behavioral choice theory [19–21] as a conceptual framework, Sit et al. [22] recently used direct observation to study electronic game behavior during extended time periods (i.e., 60 minutes continuously) and under conditions when children had choices in playing interactive or computer screen versions of the same games—bowling and running. Findings showed that children spent about half their time on the interactive versions of games and that these versions engaged children in substantially MVPA more than during