Participants will be randomized, stratified by parity, into either an intervention or minimal care group after all baseline measurements are complete (3 +/- 1 wk postpartum).
The specific aims of this project are to evaluate in overweight lactating women at 3 and 20 weeks postpartum (PP) whether an exercise and weight loss intervention, compared to a minimal care group, will:
1. Improve body composition. The working hypothesis for this aim is the intervention group will lose less lean body mass and bone mineral mass and promote more fat loss compared to the minimal care group at 20 weeks PP.
2. Promote an increase in cardiovascular fitness and strength. The working hypothesis for this aim is the intervention group will increase predicted maximal oxygen consumption and maximal strength compared to the minimal care group at 20 weeks PP.
3. Affect bone-related hormones. The working hypothesis for this aim is the intervention group will increase growth hormone and insulin-like growth factor-1 compared to the minimal care group at 20 weeks PP.
4. Improve total diet or overall pattern of food eaten. The working hypothesis for this aim, based on menu modeling with MyPyramid (16), is the intervention group will improve the quality of their intake by consuming the recommended amounts of food groups established by MyPyramid compared to the minimal care group at 20 weeks PP.
