I couldn't find anything on this using the search function, so I'm raising this question because I've found different people to have conflicting recomendations.
Obviously Coach has his athletes start strength training quite young with great results. The Chinese are notorious for starting athletes off young. I have a couple books from Tudor O. Bompa, PhD, one of the big periodization guys. One of his books, titled Total Trainign for Young Champions lists time tables for development of young athletes for different sports. I was shocked when I first saw these tables because I was always under the impression that because maximum strength increases power, and because many studies show it doesn't stunt growth, young athletes can always benefit from increasing their max strength.
However, for almost every sport, Bompa recommends maximum strength training start around the time that the Specific Training phase transitions into the High Performance Training period. For most athletes this occurs around 18 years of age. For male gymnasts, he puts the age at about 16 and goes through the end of career. He has Anatomical Adaptation from ages 8-12 and Power development from age 10 through the end of career (again for gymnasts).
In his book, Periodization: Theory and Methodology of Training, he explains his ideas why this is and uses studies to back it up. Basically, in his observation athletes that train hard at young ages generally burn out or peak around 18 years old, but they destroy the Junior level competition. After that time, they don't generally continue to improve much, or even fade and are more succeptible to injury. By contrast, the groups that began with easier multilateral training didn't perform as well in Junior level competition, but had longer healthier careers, sometimes still being strong compeditors in their 30s (this was for all sports, not gymnastics in particular).
So, I guess I can see where he's coming from, but I'd like to hear the other side of the story. Maybe this is a good question for Coach. For the athletes you begin training at very young ages, does intense maximal strength training such as planche training, ring work, etc seem to positively or negatively affect training and competition later in life?