WalkLink: Internet-based Walking Program

The investigators propose a randomized controlled trial based on the Social Networks for
Activity (SNAP) 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 308 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 additional social network intervention
(WalkLink+); and 3. Minimal treatment control.

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: physical activity, aerobic fitness, blood pressure, body
composition, and body mass index (BMI), from baseline to posttest, and at 6-month
follow-up.

2. Compare the differential effectiveness of WalkLink+ to WalkLink on change in: physical
activity, aerobic fitness, blood pressure, body composition and BMI 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, social cues for walking, social
praise/reinforcement), and physical-ecological variables (neighborhood walkability,
physical cues for walking) on WalkLink and WalkLink+ treatment outcomes.