I am 61yo. I ride a Canny r4000si. My wife is 59yo. She rides a Canny r2000si. We ride at least twice a week, maybe 40-50 miles. We ride approximately 100 miles per week. We both eat well and take vitamin and mineral supplements. She also is taking calcium and chondroitin. I was a professional bodybuilder until I was 50yo. I have slowed down, but I must say my endurance is about the same. My wife has actually gotten faster. I have been riding about 50 years. I used bicycling as an adjunct to my bodybuilding. We both go to the gym 3 times per week, and use a tandem kayak frequently. We consider ourselves in pretty decent shape. However, it is tough saying how old you are. I (we) do not feel old!