Premature birth is recognized as the single most important health problem in maternal child health in the US. Paradoxically, both failure to thrive and obesity are now known to be associated with prematurity, as are osteopenia (a condition where bone mineral density is lower than normal) and increased risk of fracture, and increased risk of cardiovascular disease later in life. We lack cohesive approaches to mitigate these profound threats to health. Despite promising new research demonstrating that physical activity can stimulate the growth of muscle and bone even during intrauterine life (perhaps through metabolic programming), there have been very few attempts to implement and study physical activity interventions in the premature baby.