I've been rather lucky in that regard. I began "serious" cycling at 13, and have more or less maintained a physically fit lifestyle over the years. My blood pressure is the same as it was when I was in high school, and my resting pulse remains low. I don't ride at much as I would like to, but I make up fir it with lots of walking, lots of stairs, and keeping up with a 5-year-old daughter. I have never been careful with what I eat, or how much, but I have always been physically active, which has gone a long way to help keeping me healthy, and preventing me from becoming overweight.