PRIMARY OBJECTIVE:
* To compare changes in levels of moderate and vigorous physical activity over 24 weeks.
SECONDARY OBJECTIVE:
* To compare changes in cardiorespiratory fitness, muscular strength and flexibility over 24 weeks.
Participants will be randomized to one of three groups. Participants in the control group will receive an activity monitor and educational materials, but will not have access to the interactive website. Participants randomized to the two intervention groups will be given access to a rewards program delivered via an interactive website, an activity monitor, and educational materials. Individual physical activity data can be viewed by study participants after uploading information from their monitors to the interactive website. One intervention group will receive minimal rewards, while the other group will receive immediate incentives as well as the minimal rewards as they move from one level to the other on the website.
After 24 weeks, changes in cardiorespiratory fitness, muscular strength, flexibility, and physical function will be compared between the two intervention groups and the control group.
