Ah, water isn't enough if you've trained hard enough, as it will take some time for water to replenish. Also, if you are still growing your body is more susceptible.
I wouldn't stress about it. If it becomes a repeating problem, than see a doctor by all means. But from what I have heard it seems to be a common problem (lots of ski instructors I know complained about the same thing, MUCH more so than any other group of people I met). And ski instructors is kind of known for hard physical labor with the legs, coupled with serious drinking...
So yeah, everything I have seen and heard points towards it...
Hehe, it's been some years now since last I had issues with it... I almost forgot how DAMN much it hurt, and how scared I got the first time, wondering "WTF!?"
I wasn't joking about the withering in pain thing... My an ex once commented that I had looked like a fish out of water...
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