Girls on the Move Intervention to Increase Physical Activity Among Middle School Girls

The purpose of this school-based trial is to test the efficacy of an intervention to increase moderate to vigorous physical activity (MVPA) among middle school girls. The 17-week \"Girls on the Move\" (GOTM) intervention has 3 components. Two individual-level components occurring during school hours include: (1) two face-to-face motivational, individually tailored counseling sessions with a school nurse, and (2) an interactive Internet-based session during which each girl receives motivational, individually tailored feedback messages (at 9 weeks). A group-level component, 90-minute Physical Activity (PA) Club provides an important venue after school that includes activities to assist girls in establishing a behavioral pattern of MVPA. The control condition will complete data collection activities and receive their usual school offerings. The investigators hypothesize that immediately post-intervention, minutes of MVPA will be greater by 16 min./wk. in the intervention than control group; At 9 months post-intervention follow-up, minutes of MVPA will be greater in the intervention than control group; and immediately post-intervention, cardiovascular (CV) fitness will be higher and body mass index (BMI) and percent body fat will be lower in the intervention than control group.