“Race” Report: USMS 10K Postal Championship

Another Friday, another long-ass postal swim at the UIC Natatorium. This time, for 10K: 200 laps of a 50-meter pool.

The 10K Postal Swim is as much a psychological challenge as physical. Even 5K is a pretty brutal distance to do as a straight pool swim. For the 10K, you do the 5K… and you’re only halfway done. So it may very well be the single toughest USMS-sanctioned event – except perhaps for the biennial open-water 25K.

I was joined by fellow distance freak Amanda Hunt, which made for less lonely laps. Heidi K. from the Smelts and my favorite U-Chicago professor were also on deck, as lap counters – which I’m told on good authority is a similarly mind-numbing experience.

My goal? 2:17:52 – my open-water 10K time from Noblesville in July.

Some reasons I might succeed in beating that time:

  • The typical advantages of pool swims over open-water – flipturns, precise navigation, negligible “conditions”
  • More hospitable water temp – 79F rather than 84-85 in Morse Reservoir

Some reasons I might not succeed:

  • I did a half-taper for Noblesville (1 week), but only 2 days rest for this
  • I wore a Blueseventy Nero for Noblesville, but only a jammer for this
  • The adrenaline factor in races vs. solo swims

What else can I say? My splits will tell a better story than my words:


(1) 5K Postal splits (dotted blue line) superimposed for comparison.
(2) Drink breaks at 2/3.5/5/6.5/8K are “adjusted out.” See 5K postal report for a description of the methodology.

Remarkably, these splits correspond fairly well with my subjective experience:

  • As the chart shows, I found a comfortable, steady pace of 1:19’s through the first 3,000m or so.
  • Then, a gradual deterioration (up to 1:22’s) into my drink break at 5,000m.
  • At the halfway point, I took extra time (23 seconds) for a nice, long swig of a recovery drink. This actually seemed to stanch the bleeding! Though I was on a trajectory for 1:23’s+, within 10 minutes of the break I had brought it back down to 1:21’s – which I maintained all the way through 9K.
  • The chart shows, as well, the wheels coming off during the last 1,000m. But not too badly – I kept it under 1:23, with just the one exception at 9,400m.

In the end: 2:16:15. Pace per 100m of 1:21.8. A few more stats:

400m splits:

  • 5:10.0, 5:16.6, 5:15.0, 5:15.7, 5:15.8
  • 5:16.5, 5:18.0, 5:18.8, 5:21.2, 5:23.5
  • 5:22.6, 5:27.2, 5:29.5, 5:29.5, 5:29.0
  • 5:28.9, 5:28.4, 5:27.1, 5:26.6, 5:27.6
  • 5:27.3, 5:26.6, 5:25.3, 5:31.4, 5:28.9

1000m splits:

  • 13:09, 13:09, 13:13, 13:25, 13:33
  • 13:45, 13:41, 13:37, 13:36, 13:43

5K splits – breaks included (no adjustment):

  • 1:06:55 (1:20.3 pace)
  • 1:09:21 (1:23.2 pace)

Nutrition & Hydration:
(HEED = “high-energy electrolyte drink” – e.g., Gatorade)
(recovery drink = includes protein/amino acids – e.g., chocolate milk, GU Brew)

  • pre-swim: HEED+2 gels
  • 2K: HEED (12.5 seconds)
  • 3.5K: HEED+gel (14.0 seconds)
  • 5K: recovery drink (23.2 seconds)
  • 6.5K: HEED+gel (17.2 seconds)
  • 8K: recovery drink (17.1 seconds)
  • total break time: 1 minute, 24 seconds
  • total volume of liquids consumed during swim: ~80 oz.

And speaking of recovery: one week ’til Big Shoulders!

Forward, march!

4 thoughts on ““Race” Report: USMS 10K Postal Championship”

  1. Good swim, man. For what it’s worth, I recovered much more quickly after the pool 10k than the open water 10k. Though the wheels fell off right at 8k again. The large pile of food I ate 30 minutes later helped.

  2. “…wheels coming off…” That’s so funny to those of us happy to maintain 1:31/100 for 300m!!!

    And my wife agrees. Lap counting is a mind-numbing experience. And all she’s had to count for me is the Brute Squad (which for me, took forever!).

    Great swim. Hope to do the same (distance, not time) in a couple years when I get back to the land of normal pools. Oh, and what sort of gel do you use?

    1. Thanks, Mike. I hadn’t heard of Brute Squad ’til I read about it on your blog. Sounds like a blast. I have a halfway decent 400 IM if I train for it, but during open-water season my non-freestyle strokes go out to pasture. 200 fly, on the other hand, I’ve never cared for.

      I’ve had good results with both GU and Hammer gels. I think I slightly prefer the taste of Hammer. The GU Roctane gels are great but too expensive.

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