Back in the Saddle (exercise bike)

I had a run in approximatly 3 months ago with a bad reaction to a switch in my blood pressure medication, and as soon as my dr. switched me back to what I was on previously, there was much improvement noted. I also had joined up with a gym membership and got involved with some personal training, but the elliptical machine did a number on me. And then thirdly I was in a car accident, and my knees hit the under the dashboard, and gratefully the x-rays showed it was a contusion of the knee cap. I have not had any more "mis-adventures", so off I went to the gym after work today and worked out for 15 minutes on the recumbent bike, and then did a little circuit training (hip abductor, leg press)...with no ill side effects. Drank plenty of fluids. So I am feeling pretty positive about that. I spoke with one of the managers at the gym, since I had already paid for training sessions and he said that I have 24 sessions available that I can use at any time, even if it is a year down the road. Well, for now I am just going to be doing my "own" personal training.
"Some people refer to Cardiovascular exercise as aerobic exercise, some people even call it 'cardio' for short. All it amounts to is exercises that involve the large muscles like legs and help make your heart and lungs stronger. Cardiovascular exercise has lots of health benefits like lowering your blood pressure, and also it can burn lots of calories - for those of you who want to lose weight.
Cardiovascular exercise is activity involving the large muscles, such as your legs. The word 'aerobic' refers to something that needs oxygen. During cardiovascular or aerobic exercise oxygen gets continuously delivered to your muscles. Outside of exercise, terms like 'aerobic bacteria' refer to bacteria that need oxygen to survive, and 'anaerobic bacteria' are ones that do not need oxygen to stay alive. To give your heart a proper workout you need to make sure that you do your cardiovacular exercise with a certain amount of intensity, but you don't want to overdo it. One way measure the amount of exertion while exercising is by monitoring your heart rate."----www.ideasforwomen.com
So my intentions are to build up my endurance and then hopefully I can get back in to a more extensive workout. My body was not ready for the elliptical today, or tomorrow, but maybe later. Here is a picture of the "mean" machine that made my legs shake like jello, my heart raced like a race horse, dizzy, etc...