Although many people are aware of the beneficial effects of physical exercise on health, they often experience difficulties in finding time and motivation to incorporate regular gym visits into their busy schedules. Exercising at home is a viable alternative, but lacks the human coaching and social support that is available in traditional exercise settings. Modern technology opens an enormous space of possibilities for enriching the in-home exercise experience with motivational coaching and social factors through interactive monitoring, feedback, and social connectedness. In this chapter we introduce an interactive social in-home exercise system, which enables the monitoring and sharing of exercise movements through an avatar in a social context (composed of a coach or other exercisers). We conduct a survey study in two user groups to explore to what extent users appreciate the use of avatars to visualize their exercise movements and to gain insight into preferences with respect to the level of personalization of avatars in various social contexts. Also, we examine the relationship between several user characteristics (body image, gender, and age) and these avatar preferences. The results show that individuals overall like the use of avatars to visualize exercise movements. Moreover, we find that the appreciation of visualizing exercise movements through an avatar and the preferences with respect to the level of personalization vary with the type of social context, with a greater appreciation for the avatar when exercising in private than when the avatar is communicated in a social context of unknown others. Also, in one group we find a greater appreciation to share the avatar with a coach than with friends or with unknown others. Finally, the results suggest that body image, gender, and age play an important role for avatar preferences.