Ask the doctor

Why do I get chest pain when I don't warm up before exercising?

Q. I work out regularly six times a week, but suffer from exercise-induced angina and what my doctor calls a vascular problem. If I start exercising without first warming up, my chest starts to feel "tight" before I've walked 100 yards. The same thing happens if I start walking after being seated for a while, such as when I walk to the baggage claim area to get my luggage after getting off a plane. If I warm up properly, though, I can walk for several miles at a pretty fast pace without any chest pain. Can you explain what is going on?

A. You are describing a fascinating occurrence called the "warm-up phenomenon" that has puzzled doctors for decades. In the clinic, it can be demonstrated by having a patient do two exercise tests, one right after the other. Many people with problems in the blood vessels nourishing the heart will be able to exercise longer and with less or no chest pain (angina) on the second exercise test. Several physiological mechanisms have been proposed for this, but no explanation has emerged.