You get very tired, and there was a certain amount of pain and you slow up. Your legs are so tired that you are in fact slowing. If you don't keep running, keep your blood circulating, the muscles stop pumping the blood back and you get dizzy. ↗
Anticipation of movement, through muscular innervation and memory, by its retention of nerve impulse images, extend the present to the limit of a second or so. ↗