It's been quite a while since I felt limited by my feet, but yesterday I definitely hit that point.  I ran 19.3 miles in a cool rain, with the second half at marathon pace.  My feet got tender by about mile 17 and I found it hard to keep my pace up, and by 19 I was ready to walk the last bit. 

Fast running seems to put a lot more pressure on the feet.  No surprise there, but I'm just realizing that I should have spent more time this summer at race pace if I want to run a fast marathon.  I've done shorter, faster races without problems, but going beyond 25k at race pace is something I haven't really practiced.

I had no injury or wear or blisters, just very tender soles.  It feels very much like I used to feel whenever pushing to a new mileage, so I'm confident I can train through this limit too.  But probably not before the Cape Cod Marathon (Oct 25).  So I may fall back to FiveFingers in order to retain my chances of breaking three hours. 

The good news is that otherwise I felt great.  My aerobic base is at least as good as it's ever been, and 19 miles felt quite comfortable, other than the sore feet.  I was actually aiming for a round 20 miles but miscalculated my turnaround point.

Wait a minute Ed, you don't have limits.  Come on now!

It seems like folks say that the wetness makes their soles sorer, faster. Perhaps it's the increased friction.  I always felt it was a cooling presence and felt it was helpful. 

But I can't say I've ever run that far or fast barefoot, so limits it is.  Good luck on your continued training.