I'm 60 and switched to a fatbike in January as my wife thought it'd make great birthday present and would keep me off the road. Which it did. I've put 800+ beach miles on it and while climbing a dune trail (say 15% slope) I happened to glance at my HRM and it said 164 and I thought "Oh, sweet". I ride a back to back century every year, look to get in 200+ hours of riding a year, ride for distance, intervals, fun, fast, slow, and I enjoy riding now more than 40 years ago. Dad lived to 92 and I'm shooting higher.