Okay, that's a slight exaggeration - but I can't ride much and I can't figure out why. This is gonna be a little long, but I want to cover everything so people can make the best evalution..
I'm 59. I started rding in early 2002 on a comfort bike, typically riding 12-13 miles, relaxing for about 90 minutes and then riding back, but I also did some much longer rides - even did a century once, though with resting and all, it took me over 12 hours!
After 9 months I got my first road style bike (actually a touring bike). At end of first year had done 4200 miles. 2nd year road more often and more longer rides - totalled 6500 miles. Third year was almost all on my first racing bike (Felt F-35). Did a lot of every other day riding and totalled 7600 miles. Fourth year was starting to do a lot of rides of 50 or more miles (sometimes over 70) and totalled 7800 miles. Fifth year started much bigger, but a schedule change because of a new job cut me down at the end so I totalled 6100. Sixth year was completely dominated by the job schedule so only managed 2200 miles and pretty much all short - 26 miles total (split into two parts usually) would be a long ride at this point.
Then I stopped at the end of December, just starting up again about 6 weeks ago and it is killing me.
My riding situation isn't long rides - at least not now. My longest is something like 15 miles and that was done in parts as I had various errands to run. Today I did 8 miles and barely made it!
What is killing me mostly is a lot of irritation to the skin under the bike shorts. Mostly it seems to hit me at the very top of the inner thighs, maybe tending a bit to the back. I know that today, after I was back in regular clothes, it felt like my jockey shorts were bunched up when I was standing, sort of toward my butt. They weren't bunched up - that was just the impression because of the pain in that area.
Now, besides being in worse shape - though certainly better than when I first started riding! - I had made a change to my bike before I resumed. I was hoping to create a situation where I could wear regular clothes because most of my riding now is going to be a lot more casual and I don't want the hassle of having to wear bike shorts for hours as I run a series of short errands for the most part.
I knew I couldn't do that with my old bike setup and I can afford another bike right now (If I could, I may look at a Trek 7000). So I put on a wider, more padded seat (Bontrager) to hopefully eliminate the need for the padded shorts.
Since the "leaning over" position is also less comfortable and would increase bunching of regular clothes, I also lowered the seat a little and slid it more forward - doesn't make me much more upright, but I figured it was better than nothing. These things were done over a period of time as each step failed to let me get by with regular clothes.
Only thing left to try that I can think of is to add a spacer to raise the stem a few inches.
So why the heck am I getting so much irritation at distances which are a tenth of what I used to do regularly, even though I'm still wearing the bike shorts? I really can't see why moving the seat position would cause that. The fact the saddle is quite different could, though I don't see why. I guess I could just give up on riding in regular cloths and go back to the old saddle, but I'd like to avoid that - and it might not be the solution anyway.