IMPACT: Inactivity Monitoring and Physical Activity Controlled Trial

Overview

As individuals age, their physical activity decreases and sedentary time increases. Even small changes in these two behaviors can greatly decrease risks for several major health problems, including cardiovascular disease, diabetes, and many cancers. Studies that use pedometers to encourage walking have successfully increased physical activity, but do not address sedentary behaviors such as television watching. The investigators propose to use a novel pedometer-like device (Jawbone Up) that encourages both increased physical activity and decreased sedentary time. First, the investigators will recruit 10 adults to participate in a brief intervention for six weeks. They will wear the wrist-based activity monitor and use a mini-tablet device to see feedback on their activity and sedentary time. They will also receive brief counseling weekly. The investigators will use this first study to investigate the basic feasibility of the intervention materials. Next, the investigators will recruit 20 adults and randomize them to receive the intervention for 12 weeks or to a waiting list. Here, the investigators will test the intervention with refinements made based on participant responses from the first small study. Our primary outcomes will be measures of feasibility and acceptability across all parts of the study. The investigators hypothesize that the intervention will be feasible and acceptable to the participants. The investigators will also measure physical activity, sedentary behavior, fitness, body fat, and psychological feelings of motivation.

Inadequate physical activity and extended bouts of sedentary time are prevalent in adults, increasing from middle age into older adulthood. Even small changes in behavior, such as standing or walking in place periodically to break up sedentary bouts, can have large effects on cardiometabolic risk factors. Pedometer-based walking interventions have demonstrated effectiveness in increasing physical activity in this population, but these interventions have not targeted sedentary behavior. Recent technological advances have produced activity monitors that are capable of intervening on both behaviors. These wrist-worn monitors provide feedback and motivation for walking as well as cues to action in the form of idle alerts. These idle alerts vibrate when the wearer has remained sedentary for an extended period of time. Several preliminary studies have shown that older adults are willing to break up their sedentary time if prompted, but interventions thus far have relied upon television commercials as a cue to action. Use of these monitors would allow idle alerts to occur throughout the day, not only during television watching periods. The purpose of the IMPACT study (Inactivity Monitoring and Physical Activity Controlled Trial) is to investigate the feasibility of using activity monitors to simultaneously target both physical activity and sedentary behavior. First, we will conduct a pre-pilot test (N = 10) over six weeks. This brief study will provide basic feasibility and acceptability information on the monitor, content for weekly sessions, and assessments. Results will be used to refine the intervention for use in a larger pilot two-arm randomized controlled trial (N = 20, 12 weeks). This trial, comparing the intervention to a wait-list control group, will test feasibility, acceptability, and health, behavioral, and psychological outcomes. The primary outcome will be physical activity, operationalized as objectively-measured minutes of moderate-vigorous intensity physical activity over seven days (SenseWear armband). We will also measure cardiorespiratory fitness, physical function, body composition, and psychosocial variables such as autonomous motivation. The results of this innovative project will provide a foundation for future intervention in sedentary behavior and potentially create a large public health impact in a population at unique risk.