In the lead up and aftermath of racing a marathon I have been contemplating predictor calculators and why they seem to be off for so many when it comes to the marathon.
A few of my friends insisted I was ready for 3:03 or even sub 3 before Columbus, but in the end I went for 3:05 and obviously that is about where I was. I chose that goal because of my half time at Buckeye Half. In the past my 10k equivalent predictor rate for the marathon was always around 4.78 to 4.83. A comparative 10k time to my 1:26:52 would be around 39 minutes and the ratio for that to my actual marathon time is 4.76. I figured best case scenario would have been just under 3:05 or a 4.75 ratio given my training was more consistent than in the past. But I also know that pacing screwed up a few of my key runs so I didn't want to be too optimistic.
I am wondering what ratio's others have and if you typically set your marathon goals based on your current shorter race performances and if any of the available calculators have been accurate for you.
I find it interesting that all of my races this year except the marathon lined up pretty well in the Daniels VO2 range, but my marathon obviously is not in that same range.
Some tools I have found useful for setting goals and getting an idea of my racing potential:
The old fashioned/simple approach: Half marathon*2 plus 10-12 minutes
Daniels VDOT Calculator: http://www.runbayou.com/jackd.htm
McMillan Running Calculator: http://www.mcmillanrunning.com/mcmillanrunningcalculator.htm
Race Time Predictor: http://www.runningforfitness.org/calc/rp.php?metres=5000&hr=0&min=22&sec=30&age=32&gender=M&Submit=Calculate
Predicting a Marathon Time: http://mysite.verizon.net/jim2wr/id70.html
The last link is one I have found intriguing. It bases the predictors on how much mileage you run. I have set up a spreadsheet to track my own personal 10k predictors and actual results along with my mileage. It seems like this time it was pretty accurate. I averaged 62 miles a week for the past 22 weeks or so and my rate ended up being 4.76 (4.78 if you based it off Perfect 10) (Note I just use the McMillan Running Calculator to get an "equivalent" 10k time for my races since I didn't run a 10k this year)
I think I still have a lot to learn about marathoning and I am excited to get faster. But it certainly is intimidating thinking about how fast I am going to need to be in these shorter distance races to achieve my ultimate marathon goals, especially if I need to do even better than most of these calculators suggest!
So my big question for myself is am I limiting myself by setting what appears to be conservative marathon goals according to all these calculators (and personal experience of others) or am I running my best marathons possible by setting a realistic goal. It seems based on my past experience that in order for those online calculators to be more accurate I am going to have to get my mileage up above 80 mpw, a tall order for those of us that aren't cranking out our easy mileage at a good clip.
Feel free to chime in on my rambling here, I am interested in others experience with calculators/goals etc. It's pretty much the down season now, so a great time to consider goals for next year!
*Edited to Add*
For an example case and since it is my blog here are some equivalent 10k times from my races leading up to Columbus and the resulting ratio
Johnnycake 5 Mile- 10k McMillan equivalent and ratio to Columbus Time 39:35/4.70
Perfect 10 Mile- 10k McMillan Equivalent and ratio to Columbus Time 38:52/4.78
Buckeye Half Marathon- 10k McMillan Equivalent and ratio to Columbus Time 39:02/4.76