I had an interesting thing happen during a tempo run last week. My RB and I headed out for a short (ish) tempo run of 6.2 miles. It was fairly warm and humid, and I know I was not acclimated to that, and perhaps a bit dehydrated even before starting. At about mile 3.5, I started to feel very tired, heavy legs. I slowed a bit and walked some, hen started running (slower) again. At about mile 4.5, I developed cramps, especially in my left calf. Walked some more. Started running again at about mile 5 and then was fine from there to the end - no more cramping or tired feeling.

Now, I've had cramps running before - that's not new. Nor is the heavy-feeling of tired legs (oh yeah - I ran intervals the day before too).  So all that was "normal" in the sense that I could easily ascribe it to not enough recovery, too hot and humid, and not enought water/electrolytes. What I can't figure out is this: why did I feel fine after walking for a bit? What made the cramping go away? I didn't drink anything, didn't take any electrolytes, didn't do anything but walk a little. All I can think is that I was a little too warm and needed to cool off a bit. But I didn't feel overly warm - it wasn't that hot out.

So I'm befuddled.