Postpartum Behavioral Observation of Diet, Image, and Exercise Study (BODIES)

Postpartum women will be recruited to participate and randomly assigned to a control group or an intervention group. Both groups will follow the data collection protocol described below; however, the intervention group will also be tasked with a self-administered physical activity intervention while the control group will be told to go about their normal routine and engage in whatever activity they would normally do. The intervention group will be asked to meet physical activity benchmarks of 10,000 steps per day and 150 minutes of moderate-to-vigorous physical activity (MVPA) per week (intervention protocol described in more detail below).

All participants will begin the study when they are between 6 weeks and 3 months postpartum and, overall, data will be collect at 4 separate visits, approximately 3 months apart, over the course of 9 months.

Testing to occur at each visit:

Body composition - Total fat mass, lean tissue mass and percentage of body fat will be assessed as participants lie in a supine position using dual-energy x-ray absorptiometry (DXA) (GE Lunar Prodigy, GE Medical Systems, Milwaukee WI).

Vascular Function Test - Indices of vascular function will be obtained in the non-dominant arm using a strain gauge plethsymograph or ultrasound. The testing entails wrapping a rubber band like device (i.e., strain gauge) around the forearm or placing an ultrasound on the skin while the subject is in a supine position. To induce a change in blood flow, a blood pressure cuff is wrapped around the upper portion of the limb (upper arm or thigh) and occluded for 5 minutes. After the 5 minute occlusion the blood pressure cuff is rapidly deflated. The change in the diameter of the strain gauge is used to quantify the change in blood flow and, in turn, the change in vascular function.