I have found that I like to gear my workouts towards more endurance based exercises. I think that really can test a client’s comfort level. I myself have gotten into running after college. I have done 4 half marathons and 2 of those I helped train and completed them with one of my clients.
I believe that the gym should be an inviting, inspiring place, and no one should feel the need to “work their way up to the gym”. The important thing is not where you start but how hard you work to improve.