I'm second guessing my choice of a pace for the Kansas City Marathon next week. Saturday was my last 8-mile run before the race. I ran part of the way with Beth Rogers, who just returned from setting a PR in the Twin Cities marathon last week. Beth and I are pretty evenly matched, except for the fact that she is younger. We both ran our last 5K race in about 27 minutes, and we run in the same Saturday pace group. Beth's PR in the Twin Cities Marathon was 4:25.
The goal pace I had chosen for the Kansas City Marathon was 4:45. I arrived at that pace using a chart that Coach Valdez created back in July for The Runners Edge speed session group. Based on a 2-mile time trail that I did that I did in July, it predicted a 5K time between a 27:30 and a 28:00, and a marathon pace of 4:40 - 4:45. That was a pretty accurate prediction of The Race for the Cure 5K which I ran a month later in 28:14; however, that was a hot day and I knew I could do better. A month after that I ran the Labor Day 5K in Leawood, KS in 27:11. That improvement was due to cooler temperatures, a flatter course, plus another month of speed session workouts. The next row up in Coach Valdez's speed session document predicted a 5K time is 26:14 -27:15, which covers my performance in the Labor Day 5K, and a marathon time of 4:32 - 4:38.
There are a number of Marathon Pace Calculators on-line. These are just a few that I found:
- http://www.marathon-calculator.com/default.asp --> 27:11 = 4:21
- http://runningtimes.com/Article.aspx?ArticleID=6765 --> 27:11 = 4:25:46
- http://www.runnersworld.co.uk/news/article.asp?UAN=1681 --> 27:11 = 4:20.27
- http://www.runaiken.com/predictor/pacer.html --> 27:11 = 4:23:48
All those on-line calculators point to a sub-4:30 pace. That does not take into account the fact that the Kansas City Marathon has three large climbs. Working in my favor is the temperature, which is forecast to be in the thirties or forties. Additionally, my week day runs have been getting faster. I clocked my fastest 4-mile hill workout a week ago with an average pace of 9:28 -- I typically run that training route about a minute/mile slower.
If I just wanted to get a decent marathon under my belt I would leave my goal pace at 4:45. If I wanted to be aggressive I would shoot for 4:30. The difference is an average pace of 10:18 vs 10:52/mile. The prediction chart on the Kansas City Marathon web site predicts a time of 4:36 based on a 27:11 5K. I would tend to trust it more than a generic marathon prediction calculator because it factors in the course elevation. As much as I want to shoot for a 4:30 pace, it would appear that the prudent thing to do is run with the 4:35 pace group. I will try to keep up with that pace group through mile 20, and then I can decide if I want to pick it up the last 6 miles. Knowing me, it is highly unlikely that I will have the energy to pull ahead at that point in the race.
