that's impressive Sandy- I ran just shy of 20 yesterday, I would have been hard pressed to run the same today 

 

MT, yeah, but your runs have a vertical dimension, mine don't.  My total elevation gain for the whole 20 miles....  96 feet.  And that is because I go through 4 underpasses.  But then again since it's so flat I can't use up hills as walking breaks so I have to run a lot of it (I use gels and digging for s-caps as my excuse for walking breaks though  .

Those flat runs can be a killer. Did almost 8 flat miles down there the other week. It was the fastest time I've done in a long time. Left me sore for several days.  Then I followed that up with a run down towards the Brazos river and there were some nice rollers with 10-12% grades and sticky mud.  Made me actually appreciate our rocks and roots in PA.