The results revealed that the positive experience of youth while playing sports and during arts enrichments activities both in terms of intrinsic motivation and concentrated effort--a combination characteristic of positive youth engagement and development--suggests additional justification to maintain or increase resources for programs in the sports and arts. Programs maximized students’ experience by reducing idle time for socializing while maximizing structured, adult-supervised activities. Data were collected from eight middle schools in two medium sized cities and one small town in three Midwestern States. All participating schools offered after-school programs; five offered federally funded 21st Century Community Learning Centers, the remaining programs were funded by local school districts and city governments. The study provided an estimate of the percentage of time after-school participants spent in various activities: sports comprised almost one-third of all time spent in the middle school after-school programs, 12 percent in arts, 11 percent socializing, and 8 percent in homework completion activities. These activities are the mainstays of the after-school programs studied. Students reported high levels of engagement while participating in sports activities and arts enrichment activities at the after-school programs, and low levels of engagement while completing homework at programs. Additionally, they reported being more engaged in activities involving both adults and peers than in activities with peers only. Both activities elicited the rare combination of high intrinsic motivation and concentration critical for positive youth developments. Inconsistent with previous research, negative affect--worry, stress, anger--were not high in sports relative to other after-school activities. Negative affect of socializing was reported as low, but positive affect and intrinsic motivation were not as high as expected. Students’ experiences of homework were decisively negative, characterized as high in apathy and low in engagement. Tables, references