My experience at the A1a Half Marathon taught me a valuable lesson. You can’t run faster over a half marathon than your fitness level obtained from training. The training must come from two components: overall weekly milage and speed work.
At the West Palm Beach Marathon I was pacing a friend who was trying to make a 3:30 finish time. This required 8 minute miles. So, we clicked off the miles as close to 8 minutes/mile as we could. I slowed off this pace slightly for the last 3 miles. My finish time 1:45:49. At the A1a Half, I decided against running the full marathon due to the expected higher temperatures in the third and fourth hours of the race. I had run a 20 miler two weeks before, so I felt that I should have obtained some fitness benefit and therefor I should run at a 7:30 min/mile pace. I hoped to break 1:40. While I did run the 20 miler, my average weekly mileage was not much higher than usual.
For the first 3 miles of the race, my pace was 7:10, 7:20, and 7:30. From there on out, my pace slowed to around 8:10 min/mile. My running buddy John had decided to go out at over 8 min/miles and pick up the pace as he went along. He was to pace a woman runner with whom he had trained. They went out at around 8:15 min/mile, also faster than the 8:30s he planned. The pace caught up with the woman and she fell back after about 4 miles. I saw her at a triangular turn around area where we were separated by between a half mile to 3/4th of a mile. I know John was between us and had 6 miles or so to close that gap. This caused me to keep focus on my form and try to keep my pace up. I ended up staying about 38 seconds ahead of him at the finish. He had been closing on me the entire time. While my pace in the second half of the run varied from 8:10s to 8:20s, his pace now quickened to sub 8s. A chart would have shown him converging on me as the race progressed. Fortunately for me, he ran out of real estate. If the race had been 14 miles, he surely would have passed me.
My lessons from this race are several. First, as John has told me repeatedly over the last year, it pays to go out slow and do a negative split for the second half. I’ve always fought this thought. I feel that if I’m ever going to hit 7:30 miles, I have to start at 7:30 miles. This is true, but I have to have 7:30 mile fitness to do so. I clearly did not and had no reason to think that I did. I had not trained a higher average base. I had not done any speed work.
My time differential between West Palm and A1a were exactly 2 seconds apart. The difference is that in the second race, I had to really strive to maintain what was easier to maintain as an average pace. I ended up with soreness the next 2 days after A1a similar to if I had run the full marathon. So running beyond my fitness level those first 3 miles and trying to hold onto 8+ pace for the second half took a much bigger physical toll on my body. My energy levels were also drained like I had run a marathon. I most likely exhausted my muscle glycogen like I had run the marathon.
All in all, I think I have to assess my race pace based on my training. On average I train from between 24 to 35 miles per week. At these levels, I can run a half at about 8 miles per mile. I can probably run a full marathon at anywhere from 3:45 to 4:00 (between 8:30 to 9:00 minute miles). To try anything more aggressive simply invites unneeded stress and cramping. If I want to shoot for a faster pace, I would need to up my average weekly mileage to probably 40 to 50 miles per week. I would also need to do speed work.
As my next scheduled marathon is at Big Sur, which is both hilly and curvy, I plan to go out at 9 min/mile pace and slow down on the hills. I plan to do incline work on the treadmill and some bridge work on the Sunrise bridge. Big Sur has a 2 mile climb from miles 10 to 12. So, time is not a goal. I will hope to finish in 4:30 to 5 hours.