Authors:

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.

"Breaking the Four-Minute Mile". The Academy of Achievement Interview, www.achievement.org. June 7, 2002.
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