Sunday, October 16, 2005

6.2 MILES VERSUS 10K

Did I actually break 39 minutes for 10K in Saturday’s race, even though I finished in 39:02? How’s that possible, you ask? Well as I was approaching the 5k mark, a light bulb went on. See, the 5k mark is in the exact same spot as the 10 mile mark of the half marathon. Sure a half marathon is 13.1 mile, but is the last 3.1 miles exactly the 3.1 miles associated with a 5k? If not, that means the last 6.2 miles of a marathon is not exactly 6.2 miles associated with a 10k.

I asked my friend Eric who certifies courses for extra cash. He said…

Marathon = 26.21876 miles (defined as exactly 42.195km) 10k = 6.2137119 miles. The difference between 10k and after 20 miles in the marathon is that the marathon is about 27 feet longer. Pretty close.

Sure, it’s “pretty close” but 27 feet is roughly 9 meters or the difference between a 1600 and a mile. Hmm, let’s do the math; 5280 feet per mile/27 feet = 195.6. I averaged 6:17 pace, which equals 377 seconds/195.6 = 1.9 seconds. Dang, still not sub-39.

6 comments:

Evan said...

This is why you often see two chip mats at 20 miles, one to get your 20 mile time, and the other to get your 10km to go time.

Chad Austin said...

Hey that makes sense. I thought it was just to make sure they recorded your 20 mile time.

How's the training? Almost taper time.

Chelle said...

Ugh...I've been tagged. Now I have to figure out whether the quote that I started my entry with that day counts as a sentence or not.

I actually think the .2 in 26.2 and 10.2 is really interesting. It makes my head hurt, but it's interesting.

Chad Austin said...

Sorry Chelle. I can't believe no one else tagged you.

I looked at the website for the 10k race. I was hoping to bust them for advertising that it was certified. However, they didn't mention certification at all.

Thomas said...

Ther's one thing I don't get: was the race 10k or 6.2 miles? If it was 10k, then there's no recalculation, and you're 10k time is still 39:02

Chad Austin said...

Thomas, this "10k" course is run on the marathon course and it started at the 20 mile mark. My point was if the last 6.2+ miles of the marathon aren't exactly a 10K then the "10K" I ran wasn't accurate. It was long by about 27 feet.