I will echo what others have said. At 51, I am stronger and have more stamina than I did in my twenties, and I frequently ride with older, stronger women as well. It does seem that my sitting bits are more delicate as my hormone levels change with age, however, and I have become more paranoid about stray aches and pains, having had first hand experience with referred pain from a herniated disc( seriously wish I'd known that pain in my hip meant a disc was about to blow...).