Ever since I ran a PR in the 5K four weeks ago, I have been anticipating this morning’s 10K race. My 5K finish time improved by almost a minute, so I have been looking forward to seeing similar improvements at the 10K distance.
Instead of achieving a new PR in the 10K, however, I failed to match not only last December’s PR of 50:47 but also last March’s 10K finish time of 52:49. I ran a 53:27.
I had set my target pace as 8:02 minutes per mile and I was able to keep this pace for the first 3 miles. In the middle of mile 4, however, I felt I had no energy and sagged to an 8:30ish pace. In mile 5 I slowed down to a 9:00ish pace and slowed down to a 9:40ish pace in mile 6.
I checked my heart rate data after the race was over. Clearly, by the time I had finished up mile 3, I was maxed out on my heart rate. In fact, in last months 5K, even though I was running faster, my heart rate was a little bit lower than it was this morning. No wonder I had trouble in the final three miles.
My lesson learned from this is that I am going to use a combination of pace and heart rate in my next race, a half marathon. If nothing else, using heart rate along with pace as a guide to how fast I run in that race will prevent me from feeling horrible at around mile 10 or mile 11.
I’m not upset about this morning’s result. I’m a non-injured runner. And non-injured runners should always be happy runners.