Ironman Steelhead: Nutritional Collapse

During my recent Ironman Steelhead 70.3, I had a nutritional brain fart of epic proportions.  This nutritional failure resulted my worse race performance to date.  Swim and Bike were fine, but once I hit the run, my nutritional plan (as executed on the bike portion) caught up to me, resulting in a bonk of biblical proportions.  I am usually very precise about my nutrition, having the requirements broken down into certain time frames and even having my Garmin set to alert me when it’s time to take nutrition.   The three problems I ran into was not adequate testing in training, not adjusting for race temperatures and taking way too much sodium.

First, I didn’t completely test my nutrition with the appropriate brick workouts.  I do recall a couple of bricks where I bonked hard, thus made the appropriate adjustments.  I also found the nutritional products that my body agreed with, thus not sending me into a code brown.  The problem was not having brick workouts that mimic a 70.3 race.

Second, my training is usually done mid-day, which means the temperatures were the highest.  Most of the time, the temperatures exceeded 85 degrees.  Race day was 70 degrees, peaking at approximately 75 degrees.  This changes the sweat rate, which should result in a nutritional adjustment, which I didn’t do.

Expanding on above, we come to the third problem:  Too much sodium.  I’m a heavy sweater, however given race day temps, I should have adjusted my sodium down.  I’ll go into more detail on this below.  But before I do, let’s start with info on what you should and shouldn’t do.

After some simple research and guidance from triathlon forums, I learned that an athlete should never try to replace the calories, sodium, etc, that is loss during the race.  From Hammer Nutrition:

"To suggest that fluids, sodium, and fuels-induced glycogen replenishment can happen at the same rate as it is spent during exercise is simply not true. Endurance exercise beyond 1-2 hours is a deficit spending entity, with proportionate return or replenishment always in arrears. The endurance exercise outcome is to postpone fatigue, not to replace all the fuel, fluids, and electrolytes lost during the event. It can’t be done, though many of us have tried."

"The human body has so many survival safeguards by which it regulates living one more minute, that when we try too hard to fulfill all its needs we interfere, doing more harm than good.”

What really stuck out from above quote is how nutrition isn’t about replacing what is loss, but postponing fatigue in order to have a successful race.  The really hard part is determining the best nutritional plan that will accomplish this. Hammer Nutrition goes on to give suggested guidelines, but the intangibles are an individuals weight, sweat rate, etc.  With that said, let’s look at the guidelines.  The picture below shows how much is burned during exercise and how much can the body absorb.  This is based on 160-165 pound person:



Given the assimilation rate, here are the guidelines per Hammer Nutrition:



Again, this is based on a 160-165 pound person.  I weigh 200 pounds, thus I need to adjust this figures slightly.  So let’s look at what I consumed during Steelhead.  My assumptions are as follows:

1. Per my Garmin 910xt, calories burnt: 993 (Swim), 1872 (Bike), 1477 (Run), 4342 (Total).  The Garmin does use HR to determine calories burnt, however there is still a margin of error.  Let’s assume it’s off by 10% for each sport.


2. Given my weight, I am going to assume I burnt 2300 MG of sodium per hour and 3500 ML fluids per hour.


3. I will use the ideal replenishment figures, less 5%.

So let’s start:

Breakfast (3:00am – 4.5 hours before race)

620 calories, 900mg sodium, 130g carbs, 900mg potassium, 16g protein.

1-Hour Before Race Start

360 calories, 580mg sodium, 64g carbs, 295mg potassium, 15g protein. (Includes 24Oz sport drink)

15-Minutes To Swim Start

100 calories, 280mg sodium, 20g carbs, 83mg potassium.

Total before race started:  1080 calories, 1760mg sodium, 214g carbs, 1278mg of potassium, 31g protein and approximately 1500ml of fluids.

Swim Time = 42:48.  Thus I burnt: 844 calories, 1630mg sodium, and 2480ml of fluids.

Per the guidelines, I should replace 295 calories, 489mg of sodium, and 694ml of fluids.  However, given my excessively high pre-race nutrition, the only real thing I’m low on is fluids.  Simple water should have gotten me through the first 30-45 minutes on the bike.

Bike Time = 2:37.  Thus I burnt 1591 calories, 5450mg of sodium, and 8750ml of fluids.

Per the guidelines, I should replace 557 calories, 1635mg sodium and 2450ml fluids.  Total consumed on the bike: 660 calories, 1595mg of sodium and 1900ml of fluids.  The calorie count I’m okay with.  I remember last year I became really hungry on the bike. This year, I brought 1/2 cliff bar, which I almost choked on trying to eat while riding.  Given my high pre-race sodium intake, I should have cut my sodium in half, at least.  In addition, I should have drank more fluids.  I could accomplish both by removing salt sticks from nutrition and adding more water.  It is on the bike that my nutritional mistakes ruined my run. 

Run Time = 2:40.  Thus I burnt 1591 calories, 5450mg of sodium, and 8750 of fluids. 

Per the guidelines, I should replace 557 calories, 1635mg of sodium and 2450ml of fluids.  Total consumed during the run:  410 calories, 940mg of sodium, and 800-900ml of fluids.  The accumulation of sodium from race start was just too much for my body.  Couple that will low fluid intake and my body was forced to take water from my muscles to absorb the sodium.  This left my muscles dehydrated, which led to the leg cramps and sick stomach. 

My nutritional plan is be rewritten.  The starting point will be going back to basics: water and gels.  I need to increase my fluid intake, especially during the bike.  At the same time, I need to significantly reduce my sodium by either sticking to just gels or waiting until the run to start with the salt tabs.