How many steps/day are enough? For older adults and special populations

Catrine Tudor-Locke, Cora L. Craig, Yukitoshi Aoyagi, Rhonda C. Bell, Karen A. Croteau, Ilse De Bourdeaudhuij, Ben Ewald, Andrew W. Gardner, Yoshiro Hatano, Lesley D. Lutes, Sandra M. Matsudo, Farah A. Ramirez-Marrero, Laura Q. Rogers, David A. Rowe, Michael D. Schmidt, Mark A. Tully, Steven N. Blair