Many instructor become so committed to teaching that they don't leave enough time for their own development. Such neglect is harmful and will diminish your practice.
You need to have a daily routine whereby you train the material throroughly. It cannot be merely dull drilling. Progress must be made. New ideas, new insights, new challenges. An instructor can spend a few hours a day addressing their own training, before ever teaching a student that day. This is not a commitment for everyone.
At some point your syllabus must be capped, and you focus deeper on your existing material. A more, more, more mentality will leave you with too much to train and no time to do it all.
In order to avoid the risk of injury, your own body must be carefully exercised in a variety of ways each day. For example, tai chi is just a portion of my own training. I also walk 5-10 miles a day (it helps the legs), perform massage and mild stretching.
The average student has no need of this level of training, but an instructor is not just a student anymore.
