TT015: Ironman & Long Distance Racing With Gordo Byrn


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Eric: “What was your rationale for going so many years without being tested for VO2 Max?”
Gordo: “It doesn’t matter. All you are going to do is give yourself an excuse not to try.  It does not matter.  Your genetics don’t matter. That’s completely my story.”


I interviewed Gordo Byrn, co-author of Going Long, and a seven time sub-9 hour Ironman finisher, including an 8:29 for a second place finish at Ironman Canada.  Gordo also won Ultraman in Hawaii.  

Gordo went from full time finance guy to not-so-fast triathlete to the elite level by doing a LOT of work (understatement).  Gordo hasn’t raced seriously in several years, but he continues to stay fully involved as a coach (

Gordo with son Axel in Colorado.

Gordo with son Axel in Colorado.

Most of the interview covered Ironman distance training and racing, but much of our discussion  provides useful information for all types of racing. Here are some of the highlights.

Ironman Cycling Calorie Race Requirements
Race time, size, and the ability to use fat for fuel will all affect calorie requirements for an Ironman. A powermeter will show you kJs (kilojoules) produced during a ride.. As a starting point, Gordo suggests eating ½ of kJ output on the bike.  For a 200 watt ride, that equates to 720 kJs and a 360 calorie requirement/hour.  

Gordo ate up to 600 calories/hour.  It’s the highest he’s seen anyone pull off and equal to that of  Scott Molina and Mark Allen. Gordo’s output was 1000kJ/hour so he was at eating at 60% of workload.

1 kJ= roughly 1 calorie burned.

Pacing is key to Ironman success and it’s easy to get wrong because of poor planning or because perceived effort is low despite a high workload.

Extra energy put into the swim results in only a few seconds per 100 gained, but if that energy is saved it can pay big dividends later in the race.  The early part of the bike for Gordo was all about settling his heart rate and fueling. Gordo rode an Olympic distance triathlon at 160bpm. The first time he ever went sub 9 in an Ironman his HR was under 130 for a lot of the first 2 hours.  The beginning of the run should feel slow.

Swim Test
Using a heart rate monitor, get a feel for pacing and perceived effort in open water with 5 loops in this pattern: easy, steady, moderately hard, all out, then steady for the final loop.  Look at the pace difference between those 100s.  Many people will find the first loop is their fastest, and they will realize they have no sense of pace in open water.

Train the ability to hold back on the swim.  Go to 3 stroke breathing – right/left/right breath, left/right/breath.  This will put a governor on your intake which will limit your pace.

In open water with pace data you’ll see that working 20-25 bpm more intensely on the swim might buy you 1-2 seconds/100.  Compare it to running, if you can run 2-3 zones high starting in the middle of the marathon the return to your race is massive.

Benchmarking your swimming

Bike pacing
Take a recent half ironman where you ran well, and take average heart rate for the bike. Use that as the heart rate ceiling for the Ironman bike.

Gordo rides Olympic at 160, Half IM at 150. His Ironman heart rate cap is 150.  On flats he is usually under 140.

Long Weekend Training
More details from Gordo here 

For a less experienced IM athlete
Friday: swim
Saturday: swim, 100 mile bike and 10k run – use bike data from the 100 mile bike and use it as the ceiling. If you don’t do the swim do a 120 mile bike.
Sunday: easier day
Monday: long run

Your best performance on the longest days provides a ceiling that you shouldn’t go over on race day.

On Not Testing His VO2 Max
Eric: “What was your rationale for going so many years without being tested [for VO2 max]?”

Gordo: “It doesn’t matter. All you are going to do is give yourself an excuse not to try.  It does not matter.  Your genetics don’t matter. That’s completely my story.”

“There are folks that trained with me my first couple years of triathlon and they just can’t figure out how I got so fast. I got fast from doing a ton of work. You’ll never find out your potential if you don’t do the work.  And if you go in, and somebody test you on a VO2, and they say, I’m like some fat, pale, hairy, finance guy, and they tell me my VO2 is 48, I’d be like wow, I could never do it. And then maybe I don’t try. And that’s not the point. The point is getting out there and trying. See what you can do. If you like it, and it fits your life, then go for it.”

Gordo was later tested at a VO2 max at 67.5 at altitude.

EnduranceCorner’s Boulder Coaching Clinic
Dec 7 &  8, 2013 in Boulder, Colorado.  Details


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