I’m not a nutritionist but I have effectively ended many Ironmans in a portaloo. Order of importance form what I learned.

1. What does your entire race day and practice day nutrition look like? Cam Wurf talked about how Froome would always say eat in training like you do in the race. Many of us will stop for snacks during a training ride. For me I switched to only eating on training rides what I will consume in the race. It’s pretty rare I stop for any goodies, definitely not on quality long rides. Same goes for breakfast and dinner night before. Tune it in. One week a month for few months leading into an IM I eat exactly like I would race week. Leaves no questions.

2. Test what works for you. There is good recommendations for carbs/salt/fluids. Test out your combo. For me I learned Gatorade + Cliff gels are best. Some other brands that have protein wreck me. This is highly individualized.

3. Environmental Conditions. When it’s 75 I do a bottle and hour plus gels. 75-90 Bottle every 45. 90+ or extremely humid I add water and salt tabs. Record your fatigue, urine color (really pay attention to this) and weight loss at various rides and adjust accordingly. Remember this on race day. Stick to it.

4. Intensity Control. Many ride/run easy in training then go harder than they think in a race. Intensity, especially as you dehydrate will really upset your stomach. I see this early season if I get a bit too fast in a run session. I know once over 90* I need to drop 5-10 watts and :10-:15 sec/mile. There’s a reason the same guys that run low 2:4x in KONA will run 2:3x in a cool race.

5. Bike fit. Yeah I know crazy right? Too aggressive position or improper fit can mess with digestion tract and air pathways. Make sure your neck and back are neutral and your position is relative to 112 miles not a 40k TT.

Scott

I would experiment with some kind of solid food to pair with the Gatorade. My first IM I did a liquid only strategy and it didn't go well on race day. For my second I kept same liquid (infinit go far) but just mixed in some Clif bars to have some solids in there on the bike. Run stayed liquid only (just had whatever I craved at each aid station - red bull, coke, Gatorade, water). That IM went perfectly, nutrition wise.

Of course, things were tested in training (for both races, but at the end of the day the liquid bike only in that first race didn't stand the test of time).

Thank you for all this information! Yes, leading up whole race week I did not follow any plan. I admit the night before the race I ate a hamburger (as earlier in the day I had my carb meal). So never practiced that and major mistake. I'll start now.

Also, practicing the whole race week nutrition I'll start to practice. Race day nutrition too and environmental conditions are a great point. Speaking of intensity control. I was going easier on my training rides. I'll have to practice some more race intensity rides to evaluate.

Honestly, all your pointers are spot on and something I need to focus on. I appreciate your time discussing your points.

Thank you for this! I will add a solid food combo to this. I will also practice this prior too. Thank you!

Solid advice here. I'll reemphasize: training should be fueled, always, like racing. Every long session is an opportunity to learn how to implement nutrition.

Great note on bike fit too. Good news: elbow cups higher and head lower is faster aerodynamically, and makes for easier gut processing and breathing.

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Dr. Alex Harrison | Founder & CEO | Sport Physiology & Performance PhD
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📱 Check out our app → Saturday: Pro Fuel & Hydration, a performance nutrition coach in your pocket.
Join us on YouTube → Saturday Morning | Ride & Run Faster and our growing Saturday User Hub

The bolded is the most important thing to work on.

Intra-race nutrition practice in training and race-day implementation might be the only thing you need to work on to solve your issues. I bet it is.

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Dr. Alex Harrison | Founder & CEO | Sport Physiology & Performance PhD
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📱 Check out our app → Saturday: Pro Fuel & Hydration, a performance nutrition coach in your pocket.
Join us on YouTube → Saturday Morning | Ride & Run Faster and our growing Saturday User Hub

Any race (regardless of distance) or hard training session I've done with pre-mixed gatorade in their bottles has upset my stomach on the bike. It's different than the powder.

Can you buy the exact Gatorade that they use in the race to train with?

Of course it might always not be a nutrition issue. Maybe you took in water on the open water swim that upset your stomach. Maybe the stress and strain of the race itself which is different to training upset your stomach.

Some great tips so far. I think you might offer a bit more detail about your race. For instance, was it hot? Did you go harder than your intended power target on the bike or start too fast on the run? Just a bit too much intensity on a hot day can cause GI distress, regardless of your nutrition.

I would also add that the 'when' of your nutrition plan is almost as important as the 'what'. If you start too late, it almost doesn't matter what you consume because you may already be in a hole you can't get out of. My understanding is that you want to take in nutrition at a steady pace and to be sure you're getting it early in the bike. Do you have a BTA? A BTA is so much better for me because with a straw right next to my face I take a sip or two every ten minutes. I never really lose track of time and forget to drink. If I had to reach for a bottle each time I wanted something, I'd do it less often and gulp it down, which might cause problems with sugar overload.

Along those lines, if you take gels of any kind, be sure to drink them with water rather than Gatorade. You don't want to flood your stomach with sugar.

My experience is that you just cannot practice your nutrition enough in training. I do most of my training indoors, even long rides, and one of the advantages is that it is easier to practice nutrition when you're not bumping down a road at 20 mph. For my first IM, I kept a spreadsheet and detailed notes for each of my long rides. I practiced and adjusted, practiced and adjusted, over and over. Once I had it dialed in, then I performed it outside because I've found that it is never as easy as I expect to stick to my plan during a race. Refilling the BTA on the fly, keeping track of the plan, remembering to drink early and often-- these are skills that are gained or refined through practice.

FWIW, I'm 136 pounds and for an IM I eventually settled on an hourly intake of 90 g. carbohydrates, 800 mg sodium and 25-30 oz. liquid. I take it in via a mix of Infinit, Gatorade Endurance, Maurten Gels, and Base salt. I start out with a couple of bottles of Infinit plus my gels and then switch to on-course Gatorade Endurance after my Infinit is finished. I prefer liquid because I feel it puts less stress on my digestive system.

Finally, as others mentioned, your nutrition leading into the race is important. Starting 2-3 days before the race I cut way back on fiber. The day or two before I add extra salt. The day before I have a large, carb-heavy breakfast and then pretty much a normal lunch and dinner in terms of proportion. Those meals consist of a mix of low fat protein and carbs. I don't have a huge breakfast the morning of the race-- bagel, yogurt, and a banana with coffee. While I'm waiting for the race to start I sip on Gatorade and take a gel with water about 45 minutes before it starts. And, of course, I make sure to stay hydrated in the days leading up to the race.

I used to have GI issues too, but the thing that helped me is just simply eating during most of my training (long workouts, short easy workouts, and even high intensity). Most of if wasn't even race specific nutrition, but it has totally eliminated my GI issues (I even ate pizza and other real foods on my long indoor rides). On race day I can take foods/gels I'm no familiar with and do just fine, where as before I could barely stomach anything.

To follow up on this point, part of the equation is also pace. Usually, we're doing our 6 hour rides, but we stop at the gas station for bottles rather than pick them up from an aid station. Even during a race sim workout, we're often putting in smallish breaks that you might not do in an actual race - down a hill or around a corner. Even getting in and out of the aerobars you're going to be (hopefully) more disciplined during the actual race than in training. And obviously, you're also swimming for more than an hour before your ride, and then expected to run a marathon after. No one does all this (rightly) in training.

One way to look at is the evolutionary flight or flight response: when the body is under stress, the last thing we need is for non-essential systems to be using vital calories in the heat of the moment. One of those non-vital systems is digestion. If you're being chased by a tiger, then blood flow to the stomach suddenly becomes a luxury. Of course, these days we're rarely chased by tigers, but from an evolutionary perspective our bodies still work the same way.

The OP may have simply put themselves under more stress in a race than in training (obviously), and the body reacted accordingly.

Some fair points though I don’t think the stoppage time is having that much impact in the context of a training week versus a race. It’s tough but it’s forced me to do a lot of solo rides so when I do stop it’s in/out with bottle water and mix up some more Gatorade.

I can get a 5-5.5 training ride down in 5.5-6hr total time when I’m hustlin.

I deal with a lot of GI distress while training and racing and my best suggestion is to anticipate it.

Nerves, waking up earlier than normal, often not sleeping well race night, then a longer harder race effort is going to result in GI distress for me regardless of what I do, so I prepare.

Imodium before I leave the hotel and more in special needs or bento box. Some folks do better with Pepto tabs, or both. If I fear I haven’t fully voided my bowels I will also administer an enema pre-race. Not fun, not sexy, not something we want to talk about, but also not a run from honey bucket to honey bucket instead of racing.

Certainly try it in your race rehearsal, but don’t be afraid to use some OTC pharma to encourage your body to play nice. AND, do all you can to avoid needing more aggressive measures, i.e. less fiber the day before a race.

The obvious thing to try would be training with the same type of Gatorade as they have on the course as others have suggested.

However, if your stomach can't handle it, could you just take more gels and drink only water? I take primarily water with a Gu roctane gel every 40 minutes or so. I alternate caf / decaf. (130 pounds.) I do this in both training and races so that my stomach is used to it. I still get some stomach upset at longer races, which I attribute to intensity and nerves. But it's manageable. You could obviously add other solids as well for calories, that you could train with. I like Honey Stinger waffles and energy chews. But my baseline is to drink only water.

I'm looking forward to this online. You suggest may help me a lot!

They're about as similar as you can get without being identical...the only ingredients the pre-mixed bottles have that the powder doesn't are water (obviously), and ascorbic acid. The only ingredient the powder has that the pre-mixed bottles don't have is calcium silicate.

So it sounds like if it's an ingredient issue, your body is reacting to the ascorbic acid.

Great info! I do think the ascorbic acid effects my stomach. My stomach seems to run too high on acid, so I don’t think it takes much.

Most GI issues are pace, fitness related not the product or thing you are eating

Gatorade endurance in bottles
WATER, SUGAR, MALTODEXTRIN, FRUCTOSE, CITRIC ACID, SODIUM CITRATE, MONOPOTASSIUM PHOSPHATE, SALT, CALCIUM LACTATE, ASCORBIC ACID (TO PROTECT FLAVOR), NATURAL FLAVOR, GUM ARABIC, MAGNESIUM OXIDE, BETA CAROTENE (COLOR)

Gatorade thirstquencher powder
Ingredients Sugar, Dextrose, Citric Acid, Natural and Artificial Flavor, Salt, Sodium Citrate, Monopotassium Phosphate, Calcium Silicate, Modified Food Starch, Yellow 5.

I think you've got regular Gatorade powder there. Here are the Gatorade Endurance powder ingredients:

SUGAR[/url], MALTODEXTRIN[/url], FRUCTOSE[/url], CITRIC ACID[/url], SODIUM CITRATE[/url], MONOPOTASSIUM PHOSPHATE[/url], SALT[/url], NATURAL FLAVOR[/url], CALCIUM LACTATE[/url], CALCIUM SILICATE[/url], MAGNESIUM OXIDE[/url], BETA CAROTENE (COLOR)[/url]

It's the powder I was referencing in post 8 that I didn't specifically name.

I did name it in the post 20.

Until recently I've never been able to purchase Gatorade Endurance Powder.

Gotcha. I assumed you were using the endurance powder.

In that case you're comparing two different drinks when you're comparing the powder you were using to the on course bottles. Even more reason for your stomach to react differently.

Ascorbic acid is Vitamin C. I'm guessing that wouldn't hurt but who knows.
I have also been trying to strategize my training nutrition to match race day. I'm going to use gatorade endurance powder and add some vitamin C to match the bottles. Might be worth a try!

I was able to really quell GI issues by starting to take in more electrolytes, and adding some solid foods to the mix. It’s been a while but those are the two things I remember making a difference.