Try not to worry. I'm in the process of getting all my tests done and I had my stress test last week. I kept thinking what are they going to do to me? I have a really bad knee and find walking very hard and painful. I was also afraid of falling. I was worried imagine myself having to run on the treadmill. I have now had the test and I needn't have worried at all! The actual time on the treadmill was only 8 minutes. I got on with all my monitiors and cables and started walking. The incline was raised and it started very slowly and the speed increased gradually. I could hold on to the bars. They will not make you run. The aim is to get your heartbeat up to a certain level and that can be achieved with walking. I never got there because my knee started hurting too much so we stopped. Try not to worry, chances are that you will be treated very nicely. Good luck!