"Having to walk backwards down the stairs because your legs feel as though they are on fire?" - OH GODYES
"You are probably suffering from DOMS." - Oh.
"Exercises that involve many eccentric contractions, such as downhill running, will result in the most severe DOMS. This has been shown to be the result of more muscle cell damage than is seen with typical concentric contractions, in which a muscle successfully shortens during contraction against a load. "
Oh, I see...downhill running...the most severe DOMS, huh?
In fact, there's even a journal article WRITTEN ON IT (actually, I found several academic articles written on the subject of the severity of DOMS from downhill running*):
"Eccentric activation and muscle damage: biomechanical and physiological considerations during downhill running." (Division of Health & Human Performance. British Journal of Sports Medicine, 1995 June;29(2): 89–94.)
Here was their abstract:
An eccentric muscle activation is the controlled lengthening of the muscle under tension. Functionally, most leg muscles work eccentrically for some part of a normal gait cycle, to support the weight of the body against gravity and to absorb shock. During downhill running the role of eccentric work of the 'anti-gravity' muscles--knee extensors, muscles of the anterior and posterior tibial compartments and hip extensors--is accentuated. The purpose of this paper is to review the relationship between eccentric muscle activation and muscle damage, particularly as it relates to running, and specifically, downhill running.
And what did they find? Well, the majority of articles I found basically say that because downhill running is a much more functional activity that combines concentric and eccentric exercise, the physiological consequences of it are much greater.
Anyway, if you haven't guessed by now, I am so sore that I have to use my arm strength to pull myself out of a chair, I can't walk down stairs, my quads are randomly giving out when I'm standing (causing me to stumble), I didn't sleep well last night because every time my quads so much as touched it woke me up from the pain, and I'm feeling all sort of weird twitching going on. I wasn't even this sore after Vineman!
It's really fun.
And how does one reduce the damage and severity of DOMS in the future? Do more of it. That's basically the answer. (Duh! I knew that...)
Except I think next time I won't pick one of the highest points in the county to run down from. That might be smart.