Pushing him a little more

My ds knows how to play people that do not know him very well. I am not sure where or why, but he seems to resist new things that many feel uncomfortable pushing him.
Of course I am not one of those people.
This is a consistent issue that I have encountered throughout the years. Example:
When he was taking Karate, his sensei would do the stretches with him. With the butterfly stretch, I knew that he was more flexible than he presented himself in class; even after being told to go farther by both the sensei and myself.
His recent resistance was toward some of the BB exercises at the center. So I strapped on my thinking cap and thought how was I going to help him to do this exercises in a positive way. When all else falls, bribery works. I simply stated that we needed to do these exercises to get better and if he does them without complaining, we will go out to dinner (with my dh coming with us, I was planning a dinner out anyway).
Now I know what you are thinking, why are you resorting to bribery when it comes to getting your child to do anything? I only use this tool as a last resort. For most things, he is willing to change, advance or evolve. Ds has done most of the exercises without resistance. He's even advanced to higher levels of the exercises on his own will because he's interested in getting to do more advance moves that he thinks would be cool to do. The other thing that helps with the exercises is that he sees us practicing what we preach.
By the way, Dr. Melillo's next book, Reconnected Kid, is out. I have just begun to read it and am very excited about it.
Have a wonderful Friday!