Racing hard is painful business. As athletes, I think we sometimes forget that because we train so hard and feel so fit that we want that special performance to be "magical.". But here's the reality- going faster than you've ever gone before is never going to feel good. It might sometimes, or maybe once in your life, but those days are few and far between. On most days a race is going to hurt and hurt a lot.
Human beings naturally shy away from pain. Whether it's physical, mental, or emotional, the point is that we don't like it and our instinct is to avoid pain at all costs. That's why endurance sports are such a beautiful and scary thing. The best athletes are rewarded for their ability to ignore pain and push past barriers that the body and mind set up to protect itself. How many times have you competed in some sort of sporting event where you walked away knowing that a small part of you backed off the effort when it got hard? I know have. It's a natural tendency and motivation plays a big part in whether we push against and through that pain barrier or back off and settle back into our "comfortably hard" zone.
Our motivation during a workout or event can be closely matched with our expectation of how hard it feels with how hard we think it should feel. Steve Magness wrote a blog post about this similar concept explaining why a bad race hurts more than a good race. I think this is true but sometimes I think athletes shy away from achieving their best performance because the race starts hurting a lot earlier on than they think it should.
I remember one race this happened to me. I was running a 10k in Arkansas the day after I'd competed in an Olympic distance triathlon (mistake #1). About halfway through the race I was already suffering quite a bit (probably due in part to that triathlon the day before). I had felt really good that morning so I expected to float through the race without having to get too uncomfortable. My mind started playing tricks on itself as I talked myself into slowing down because I was "only" halfway through and there was no way I could hold my pace for the length of the event. I hadn't signed up for the race expecting it to be this painful and so I started slowing down. I thought I was still running hard (because it still hurt) but in reality I had backed off that top end. Then I crossed the 8k mark and realized that I was on pace to set a PR for my open 10k that day. That changed things a bit! All of a sudden the pain didn't matter as much anymore because I wasn't just running the race, I was running it faster than I ever had for that distance. My pain scale shifted because now my expectations were that it should hurt and I was going fast.
Learning to deal with high levels of pain is important to achieving maximum results during an endurance event. I think most of us inherently know this but we don't actually like it once the moment comes. If you think you're body is fit enough to achieve a peak performance, then make sure you're mind is fit enough to produce the effort needed for that same performance. Don't be surprised that doing your best may come at a cost of hurting a lot. Learning to push back that pain barrier during competition may just be the thing that propels you into the next level of performance.