WalkLink: Internet-based Walking Program

The investigators propose a randomized controlled trial based on the Behavioral Ecological Model to evaluate: (1) the effectiveness of an internet-based fitness walking program delivered to patients with risk factors for cardiovascular disease and stroke; and (2) the contribution of social support networks to enhancing the effectiveness of the internet-based fitness walking program. The investigators will recruit 310 patients who are sedentary and have risk factors for cardiovascular disease and randomly assign them to one of the following groups: 1. Internet-based fitness walking program (WalkLink); 2. Internet-based fitness walking program plus social support network intervention (WalkLink+); and 3. Minimal treatment control group (usual care).

The primary specific aims of this study are to:

1. Evaluate the effects of WalkLink and WalkLink+ relative to a minimal treatment control group on change in: aerobic fitness, walking quantity, blood pressure, body composition, body mass index (BMI), and amount and frequency of moderate and vigorous walking and physical activity from baseline to posttest, and at 6-month follow-up.
2. Compare the differential effectiveness of WalkLink+ to WalkLink on change in: aerobic fitness, walking quantity, blood pressure, body composition, BMI, and amount and frequency of moderate and vigorous walking and physical activity from baseline to posttest, and at 6-month follow-up.
3. Evaluate the mediator and moderator effects of selected individual-level self-management skills (goal setting, planning, self-monitoring), social support variables (number of activity partners and networks, social cues for walking, social praise/reinforcement), and physical-ecological variables (neighborhood walkability, physical cues for walking) on WalkLink and WalkLink+ treatment outcomes.