Don't care. I'm just glad to have lost some 60lb and I don't think I would have done that with a simple 30-60 min a day a few days a week. Riding my bike excessively is far, far from the most dangerous things I've done, and living the longest life possible is not my most important goals in life. Enjoying whatever time I have is my goal and riding my bike is, for now, a major part of that enjoyment.