I posted in the 10K forum about my recent HARD "crash and burn"/ "hit the wall" experience at the 19K mark of an intended 24 klm run. Considering that this run was done at a pace over 1 minute slower than a previous 20K run - why did I crash in this one? I have always thought that if I ever did "hit the wall" in the way it is commonly described after around 2+ hours of running , I would simply walk the rest of the distance. yesterday I had to ring for my wife to pick me up - I told her where I would be - sitting on a seat at the bottom of a long hill. I was at the top of the hill when I rang her and thought, because I was disappointed to be feeling this way, I would "jog" to the bottom of the hill. I could not do it!!! - I was truly finished and was barely able to walk down that hill to the appointed pickup place.
It was a warm and extremely humid day and my perspiration levels were through the roof - I have never been so "wet" at the end of any other run - and I had drunk less than 500 mls over the 2.5 hours. So - upon reflection I can now see what my problem was, severe dehydration. BUT - I was never once "thirsty" during the run in spite of the heat , humidity and my (now) obvious levels of perspiration.