My horse Jerry used to be a school horse, or a lesson horse, which meant he had several different people riding him throughout the week. He never had much muscle then, and he always seemed tired after I rode him.
It's been about two and a half months since I bought him, and I'm already starting to see a great increase in his neck and hindquarter muscles.
Why would he be getting more muscle now that one person is riding him instead of a lot of different people? Can someone explain?