These social support interventions focus on changing physical activity behavior through building, strengthening, and maintaining social networks that provide supportive relationships for behavior change (e.g., setting up a buddy system, making contracts with others to complete specified levels of physical activity, or setting up walking groups or other groups to provide friendship and support).

The Community Preventive Services Task Force recommends implementing efforts made in community settings to provide social support for increasing physical activity based on strong evidence of their effectiveness in increasing physical activity and improving physical fitness among adults.

Results from the Systematic Reviews:
Nine studies qualified for review.

• In all nine studies reviewed, social support interventions in community settings were effective in getting people to be more physically active, as measured by various indicators (e.g., blocks walked or flights of stairs climbed daily, frequency of attending exercise sessions, or minutes spent in physical activity).
-Time spent being physically active: median increase of 44.2% (interquartile interval: 19.9% to 45.6%; 5 study arms)
-Frequency of physical activity: median increase of 19.6% (interquartile interval: 14.6% to 57.6%; 6 study arms)
-Aerobic capacity: median net increase in of 4.7% (interquartile interval: 3.3% to 6.1%; 5 study arms)
-One study found that those who received more frequent support were more active than those who received less frequent support, although both highly structured and less formal support were equally effective.
• These interventions also improved participants' fitness levels, lowered their percentage of body fat, increased their knowledge about exercise, and improved their confidence in their ability to exercise.
• Interventions included in the review involved either creating new social networks or working within existing networks in a social setting outside the family, such as in the workplace.
• These interventions were effective in various settings including communities, worksites, and universities, among men and women, adults of different ages, and both sedentary people and those who were already active.