This is very true. I have been riding pretty steady since the early 70's, I raced for several years, and was in very good shape. I'm still in good shape, but my goal is not so much to gain, as it is to maintain as much as I can. There are still seasonal fluctuations because skiing and other activities tend to lower my mileage. These other interests help provide variety and keep me anxious to get back on the bike. I am fortunate, or unfortunately depending on how you look at it, to have a wife that does triathlons. I ride with her a lot on her training rides, which helps me slow the inevitable. We also manage to do at least one major bike tour a year. Four years ago we averaged 50 miles a day for 74 consecutive days on a cross country ride. We also just completed a 2900 mile fully self contained ride through Europe this summer. I know I will never ride like I used to; but like most of us, I want to do my best. However, and more importantly, I still enjoy riding my bike as much as ever!