I have memories of being in my early 30s (which isn't that long ago!), and getting back on the bike after some break or another and finding the first 3 weeks of cycling quite difficult. After which time 20 - 25mph cruising speeds seemed to be common place, and didn't really require that much effort.
Now in my late 30s, I seem to struggle to maintain a speed of 20mph, and more often than not cruise at somewhere between 15 and 18mph. After more than a year and a half of what seems like a hard slog, I still feel disappointed with the apparent lack of progress.
Maybe I just have to face the fact that I'm an almost 40 year old asthmatic who is never going to get that speed back again!
There are some positives though, in terms of stamina I am probably fitter than I have ever been, or at least in the last 10 years anyhow. I now cycle more miles than I have ever cycled (>3000 per year), and not so long ago the thought of cycling 50 miles in one outing seemed like an almost impossible task. I remember reading those tweets from other people and wondering how they did it. Now a 50 mile cycle is a once a month activity which I look forward to.
There are still improvements that can be made with lifestyle however, I am still about 3 stone heavier than I should be, and that is going to be the focus of my attention in the new year. I did loose about a stone when I started cycling again, but since that initial loss my weight has remained static. Unfortunately though I'm running out of things to fix!
For now I still refuse to believe that my speed is gone for good, only time will tell...