Videogames, similar to these initial exergame results, show decline in playing frequency as games become familiar and the novelty wears. One of the most successful forms of videogaming has been the advent of synchronous multi-player online gaming. Games such as Blizzard's World of Warcraft are played online by millions of people. Specifically, videogames can been played with others online. Gamers may form online social clubs (teams, leagues or "guilds") allowing them to play regularly with the same group of people. The social attachments formed by players can be as strong as those held in the "physical" world, contributing to an extremely long maintenance playtime in comparison to ordinary gaming. To our knowledge, exergames with these properties have not been examined with families in the home. Nevertheless, there is an extensive body of research on the effects of social contexts in supporting physical activity adherence behaviour that suggest that people are more likely to sustain their involvement in a physical activity setting if they participate in social, or group-based, settings rather than on their own. In the context of this trial, if Canadian youth are provided with the opportunity to be part of a virtual group (through online synchronous game play), this will likely support their sense of social connectedness in relation to other youth in that condition, a greater degree of enjoyment of the intervention (affective judgements), and thereafter sustain their adherence behaviours.