Intentionally inflicting as much pain as possible? Why would you do that? I always give the same reply.
"What would you do if you heard a gun?" And it's satisfying, exhilarating, fantastic, stimulating...but I don't say those words out loud. That would be weird. People just don't understand.
Yeah, when you hear that you have to go run ten miles, you can't help but groan. But the thing is once you've started and you feel the ground beneath your feet and your legs striking forcefully beneath you, it's as though you could go for 1000 miles. And when your lungs feel as though they're about to burst and your heart is beating as fast as it can, you know that you are becoming stronger. You will be able to push even harder tomorrow, and the day after that. You forget any pain there was, and you smile to yourself.
And then there's the sound of the gun, starting a stampede. The adrenaline surge carries you so far, so fast. And you are running for as fast and as long as you can. Though it is a concern off the track, you forget to think about your time. All there is is the reminder to move your arms and not focus on anything painful.
Your vision is shaking and your heart is pounding. You are on your toes, striding out as far as you can.
As fast as your legs will let you go.
Run until you feel as though you're about to die. Once you have done that, you will be strong. You will endure. And you will race faster.
But it's a small price to pay.