DEAR DR. DONOHUE: I am a 64-year-old male, 6 feet tall and 215 pounds. I have never been an elite athlete, but I always have participated in sports and exercise. Currently I walk, bike and rollerblade. Since I move slower than I used to, I spend more time at it. My problem is my breathing. Four years ago, I had a consulting job at higher elevations and had a difficult time breathing.
More...