A couple of years ago I got myself a winter training machine and set it up to simulate a time trial, just to see how I'd do. Thinking I'm a fit windsurfer, paddler and so on, I thought it seemed pretty fast... when I checked the time/distance chart, my time came out as comparable to an 82 year old... trouble is, I was 48 at the time! (I'm not saying it was me that ticked the 80+ box, by the way.)