By discussing your findings with them in a way that points out BOTH the things that they did well at (assuming that they did well at something, but if not, then by assuring them that with help, progress will be made), and by giving them concrete advise on how you will help them improve on what you’ve found (discussing the ‘game plan’ if you will).
your client is already motivated to the point that s/he has approached you for personal training. While it may have been at the recommendation of a doctor, there is recognition of the need to change something.
People who have never exercised before in a formalized setting are often intimidated and may think that there is nothing they can do or do right. Since you have assessed you have a starting point. I found it always helpful to give clients a sense of success in every session I have with them. Particularly at the early stages, I only ask them to do something when I am rather certain that they can do it. As they gain confidence, you can challenge them at times with things that are a bit above their heads – but they have to be within their grasp.
It is also helpful to point out to clients things like “remember when you first tried this, and how hard it was for you?” People forget, and this can be very motivating for them to look back and see how far they have already covered.
Wish you good luck.
Good question. On top of what Jocelyn mentioned I would add that coming up with attainable and realistic goals are another great way to keep them focused and motivated. You need to keep an open communication channel with him or her and be a good listener. Lead by example and always be there to help them when things get tough for them and also have a good sense of humor.