Testing Adaptive Interventions to Improve Physical Activity for Sedentary Women

The participant will receive an enhanced physical activity monitor treatment for weeks 1-8, which includes goal setting with a physical activity prescription, and self-monitoring with a physical activity monitor.

"The participant will receive an enhanced physical activity monitor treatment for weeks 1-8, which includes goal setting with a physical activity prescription, and self-monitoring with a physical activity monitor.~In addition, these participants will receive motivational text messages. For participants who remain less than halfway to their daily step goal by a designated daily time, a motivational text message with a strategy to overcome barriers will be sent."

"Nonresponders to the enhanced physical activity monitor, will receive an augmented treatment.~The participant will continue to receive an enhanced physical activity monitor treatment for weeks 9-34.~In addition they will receive ten brief motivational telephone calls, made by an interventionist, every two to three weeks during weeks 9-34."

"Nonresponders to the enhanced physical activity monitor, will receive an augmented treatment.~The participant will continue to receive an enhanced physical activity monitor treatment for weeks 9-34.~In addition, the participant will take part in five 45-minute group meetings held every four to six weeks during Weeks 9-34."

"Nonresponders to the enhanced physical activity monitor plus text messaging, will receive an augmented treatment.~The participant will continue to receive an enhanced physical activity monitor treatment for weeks 9-34.~In addition, these participants will continue to receive motivational text messages. For participants who remain less than halfway to their daily step goal by a designated daily time, a motivational text message with a strategy to overcome barriers will be sent.~In addition they will receive ten brief motivational telephone calls, made by an interventionist, every two to three weeks during weeks 9-34."

"Nonresponders to the enhanced physical activity monitor plus text messaging, will receive an augmented treatment.~The participant will continue to receive an enhanced physical activity monitor treatment for weeks 9-34.~In addition, these participants will continue to receive motivational text messages. For participants who remain less than halfway to their daily step goal by a designated daily time, a motivational text message with a strategy to overcome barriers will be sent.~In addition, the participant will take part in five 45-minute group meetings held every four to six weeks during Weeks 9-34."

During Weeks 35-50, all women will receive enhanced physical activity monitors only.