I attempted to break into an all out sprint but it felt as if my lungs were on fire or as if they would collapse at any second. But I ran. I ran and I ran and still I ran some more. I could feel the lactic acid building up in my calves and thighs, searing muscles, eating away my tendons and ligaments (the important stuff that keeps you from needing a walker or wheel chair when you sink slowly into your twilight years). My lower back tightened and my muscles suffered little spastic craps that hit various points throughout my body as if I had been assailed by twelve dozen spear men prodding and poking me.
There are two aspects of pain tolerance: potency (or the intensity of pain you can endure) and duration (the length of time you can endure said pain)
Someone told me once that the more you run the easier it gets. I'm pretty sure that they were lying. I don't think it ever gets easier. I don't think the pain ever goes away. I do think however that one develops a tolerance for the pain via a cerebral device known as motivation.
Looking back I can only remember one time in my life that I ever enjoyed running. There could have been more but my brain blocked them out in a ploy for self preservation. I would go so far as to say that even in my childhood I could only stomach running for short periods of time. I was a natural-born sprinter. But even that was reserved for running home for dinner or escaping the crazy moose that grazed on willow trees behind my house in Alaska.
Once late teen and early adulthood hit I had an excuse not to run. I was a lazy, pot smoking hippie who was "not in a hurry to get anywhere, man". Sure, I walked a lot. I walked every where, after all car emissions were destroying the ozone layer and more importantly my soul. But running? Never, man. Just relax.
Then, in some mad attempt to assimilate to society (you know those folk with the minivans and 1.5 kids, a mortgage and six maxed out credit cards), I decided to join the military as it was a steady job that would allow me to pay the bills and settle down and be normal and...
Yeah, I forgot about all the running. So here I am, running a mile and a half, cursing the packs of cigarettes, the soda and the fast food. Here I am. My watch says 7 minutes at the half way point. If I keep up the same pace I'll hit the finish line at 14 minutes. The first 7 minutes were bad enough. Hopelessness settles over me. I slow, I walk. People yell at me, trying to motivate me. My lungs burn, my body aches. I move forward again, out of embarrassment more than anything else. I keep my eyes on the ground, trying to forget about how far away the end is. I try to widen my stride. I stretch out. One tile per reach. Step on a crack break your mother's back. I sing in my head some song from some cartoon I remember as a child. I think about what I'm going to do when this is over. I find whatever motivation or distraction I can to help me through this. I look up. There is only 100 yards left. I'm a natural-born sprinter. I dig in. I find what I'm looking for, that gritty determination to die trying. Suddenly, I'm flying. faster than the speeding cars in the road beside me. Faster than the wind. I cross the finish line. I hear a number "13:45!" It's over. I pass. Another six months before I have to do it again.