IMPACT: Inactivity Monitoring and Physical Activity Controlled Trial

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.

Inclusion criteria

• Willing to be randomized to either group

Exclusion criteria

• Age below 55 or above 79
• Unable to read and understand English
• Unable to read words in standard applications on a mobile device 5 - 10" large
• Unable to find transportation to the study location
• Investigator overseeing initial fitness test does not approve participation in the study
• Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q, items 1 - 4). Reporting taking medicine for blood pressure on this questionnaire will require a doctor's note to participate.
• Unable to walk for exercise (self-report)
• Report current symptoms of alcohol or substance dependence
• Plans to move away from the Galveston-Houston area or to be out of town for more than 1 week during the study period
• Unwillingness to report drugs taken for comorbidities such as hypertension or diabetes
• Stroke, hip fracture, hip or knee replacement, or spinal surgery in the past 6 months
• Participant is active (60 minutes of moderate-vigorous intensity activity per week or more)
• Participant watches little television (120 minutes per day or less)
• BMI is under 25 kg/m2 or over 35 kg/m2
• Another member of the household is a participant or staff member on this trial
• Currently a participant in a physical activity research trial
• Recently (less than six months ago) completed a physical activity research trial
• Report a history of orthopedic complications that would prevent optimal participation in the physical activities prescribed (e.g., heel spurs, severe arthritis - may be eligible, but a doctor's note will be required)
• Current smoker
• Currently uses a Jawbone Up or similar activity monitor device