I want to know what is the phenomenon, or if it exists, that makes you stay at the same pace after about 2 hours of running. Changing speeds whether its to slow down or speed up feels slightly painful at first. Several times in marathons I get stuck in problem and end up running very slow to try to get rid of the pain with no success. A few times I've run at speeds that are faster than normal or slower than normal where that pace became the only comfortable pace after a few hours. Today even trying to walk up an incline my legs almost automatically continue to move at a similar cadence and slowing down didnt feel good.
Actually once I managed to run alot faster than normal for 20 miles and I want to repeat this. The pace was a normal short 6 mile pace for me, so Im wondering why or how it was possible. Couldnt repeat it though. Today it was similar but at a slower pace where I couldn't speed up or slow down easily. If the phenomenon exists I'd like to manipulate it to assist in running a fast marathon or half or to help do an ultra.