High And Low Impact Physical Activity Substitution And Pediatric Bone Density: 603 Board #5 May 31 1. (May 2017) - Mitchell, Jonathan A.; Cousminer, Diana L.; Chesi, Alessandra; McCormack, Shana E.; Kalkwarf, Heidi J.; Lappe, Joan M.; Gilsanz, Vicente; Oberfield, Sharon E.; Shepherd, John A.; Kelly, Andrea; Grant, Struan FA