Originally Posted by
Voodoo76
I think you are looking at part of it backwards. Z2 is what it is, based on tested FTP. It changes even within a season. You don’t drive fitness up by arbitrarily changing the Zone. Particularly with low intensity you want progression of time in Zone, then test, then adjust the zone based on the new test. Rinse, repeat. Just as rigorous, but all the numbers are lower.
I would agree an aggressive group ride with myself at 35 would be harder. Because 62 year old me would be riding at a much higher % of Threshold.
Not to argue, but I know that zones are derived on FTP. So basically your FTP has decreased with age just like your zone power has. Result in the same thing is my point which is what we agree about in your last sentence. At 62, you are riding at a higher % of threshold compared to when you were 35 for the same high exertion ride.. Your threshold isn't as high as an older rider. If you think about it, it is somewhat self fulfilling in spite of rinse and repeat. You just aren't going to rinse and repeat and elevate your FTP and related zones back to where they were when you 35...or...you were undertraining at 35. That is what the aging process does. It robs us of our ability to have as high a FTP as we had when we were young...or we did not train adequately when we were young.
We agree on your last comment in bold and why I believe more recovery is required after a high intensity group ride for an older rider.