Hubris
So, while I was at PT (that's physical therapy, for you young 'uns who have no need of it) getting electricity shot through my tender, tender kneecaps, I mock-complained that if Lance Armstrong can do triathlons at the ripe old age of 37, I should be able to do my modest six-days-a-week training schedule without excruciating, crippling pain.
And my PT quipped, yeah, Lance's abilities have nothing to do with genes...
Apparently my genes are at war with me. Being a 40-something athlete is, I am finding, a constant balancing act between trying to generate enough activity to keep oneself strong and healthy and having to curtail said healthy activity because one's body won't tolerate it.
I swear, the demands I make of this body are modest. I don't run ten miles at a time. I run four. I swim for 45 minutes. I ride my bike at a modest pace, in a not-terribly-hilly environment, a couple of times a week. I take a rest day, whether I want to or not (I hate them, to be honest).
And yet. Here I am, the day after a ride, and my knees won't work. They won't bend. They are screaming at me. I am, occasionally, screaming back at them. I gritted my teeth throughout the PT. I am a tough-ass little cookie, after all. But holy shit, this hurts.
I never take unnecessary medications. And yet I gulped down a giant prescription-strength Naproxen this morning. I iced the hell out of everything.
None of it helped. The PT said it'll get better, that I should stretch before and after rides, that I should do nothing but swim this week, and that I should get those shorter cranks ASAP. Righty-ho.
Ouch.
PS. Yes, my ass hurts, too. Boo hoo hoo.
PS2. Fuck you, Lance. Fucking superhuman freak. Bastard.
PS3. And fuck all you cute little boys at the bike shop. I bet your knees don't hurt you at all, you sexy little brats. I hate you.

I like the title.
Yeah you have to be careful about knees - I've got issues stemming from the age of eight when I almost severed my leg right through my kneecap. That was sore. But the arthritis that started at 16 was worse, I believe.
No so much with moderation in all things? I know, I know - 4 miles IS moderation.
Is the fixed gear going to help or hurt with this?
Well, it remains to be seen. PT is of the opinion that any strengthening of the quads is good for the knees, and the fixed-gear will strengthen the quads like nobody's business. But I am nervous that the knees won't heal enough to deal with the early stages of fixed-gear riding, wherein one's knees have to adjust to the fact that There Are No Other Gears.
If I have to choose between running and riding, the running is toast, baby. Though it does have the added benefit of making me higher than a kite.