FOR YEARS NOW, ADULTS have been told by medical and fitness experts that strength training is a crucial part of a stable exercise regimen for overall health. We know that cardiovascular fitness is fantastic, but alone, it isn't enough to keep our bones healthy and our muscles from degenerating as we age. But when it comes to kids' fitness, historically the exercise focus has been cardiovascular in nature. Yet research has revealed that even children 12 and under can reap the health and physical fitness rewards of strength training. To be most effective, it must be done properly and safely.