I am a walker now but hope to be a runner someday. I am 48 and really overweight, but I have a goal to lose 50 lbs in the next 6 months. I know this is kind of late in life to start wanting to run, but I have heard of people doing it. My problem is that even at a 4 mph walk my heart rate goes up to what it would be for most runners, so I have to do this gradually. About eating before doing cardio, I take a banana with me on the way to the gym and eat it in the car along with some water. It has tons of potassium and is good for the heart!