A Simple Ironman Nutrition Plan: Everything You Need To Know

Nutrition plans, especially those designed for Ironman or other triathlons, can be especially complicated. Calorie counting, food measuring, calculations for resting metabolic rate, the list goes on.

The thing is, it doesn’t need to be that way.

Sure, if you’re an elite, olympic athlete or you’re gunning for an age group podium spot at Kona, you might work with a private nutritionist who counts your grains of rice for optimal performance, but most of us are not that guy or gal.

The vast majority of triathletes seeking proper nutrition, are regular people, with regular jobs, who contain entirely to little free time to incorporate such minute measurements & calculations into their daily lives.

Hence, the creation of this Ironman nutrition plan.

Learn the basics, the guidelines, the do’s and don’ts, and be well on your way to properly fueling your body (properly) for the exertion required when following an Ironman training plan.

What makes for a good triathlon nutrition plan?

The basics of any good Ironman nutrition plan are pretty simple: eat quality, whole and real foods, allow for flexibility in portion based on your bodies need, and variety (so you don’t bore yourself to death with the same food over and over again).

For even more detail, check out our first Podcast episode all about Ironman nutrition.

Eat real food

Most grocery stores are set up in a similar fashion; fresh foods on the outside walls, aisles of processed food in between.

99.9% of everything you should be eating when training for (anything really, but especially) an Ironman exists on those outer walls.

Of course, we’re talking about fresh fruits & vegetables, seafood, meats and poultry, with the occasional trip to an aisle for olive oil and spices.

A good rule of thumb to follow is this: if it’s going to go bad less than 10 days from when you buy it, it’s probably the right food.

With an increased focus on “shelf life” and lowering production cost, over the last 50 years, more and more low-quality foods have hit the shelves. TV-dinners, microwavable meals, powder and sugar filled drinks, all make for (sometimes) tasty and convenient treats, but they come at the cost of benefit to the body.

Brittany Jones, Continuing Education Chair for the South Carolina Academy of Nutrition and Dietetics (SCAND), says: “As a Registered Dietitian, I encourage my patients to focus on “whole foods”. These are foods that are more nutrient dense, compared to “processed foods” that are simply high in energy. The difference? Nutrient dense foods provide a heavy dose of nutrients for your body. These include vitamins, fiber, key minerals with low added sugar and fat, while inversely, energy dense foods (aka, high calorie foods) provide many calories with little value to your body.”

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Training for an Ironman takes a long time. For some, it can take well over a year to cross that finish line.

If you’re fully committed to the process, and also to a triathlon diet plan, it’s key that the plan you’re following be flexible.

Everyone’s body is different, and requires a slightly different treatment. This is especially true when it comes to food!

Consider the 3 main body types that make up most of humanity today:

  • Ectomorph – Long limbed, and not particularly muscular
  • Mesomorph – Proportionally built & build muscle easily (cue jealousy)
  • Endomorph – Shorter limbs, and store fat more easily

3 individuals of the same weight, but with each of these 3 different body types, would need to approach their diet plan and food intake very differently.

For ectomorphs, with a fast metabolism, you’d be better off focusing on ‘good fats’ and moderate protein intake, pairing carbohydrate intake to your energy levels.

Endomorphs, on the other hand, need to focus a bit more on lean proteins and quality fats, while limiting carbohydrate intake.

Those mesomorphs in the middle, can afford a bit more flexibility on the ratios of their food groups, though regulation is still needed.

In addition to your body type, there’s also that “social life” thing that you have.

Most serious triathlon nutrition plans (and we’ll cover it here too) discuss limiting or eliminating things like processed sugar and alcohol.

It’s important to note, however, that you’re a human being (probably?) and on your birthday, you might just want a slice of cake and a beer! And you know what? That’s ok! You can still enjoy life when you’re following a nutrition plan, so long as it’s done in moderation.

All of this to say, an Ironman nutrition plan that offers flexibility based on your body type (and social life), and a simple way to make those adjustments, is key for anyone tackling such a race.


We all know that 1 guy or girl that can eat the same thing, every meal, every day. If that’s you, you can simply skip this section.

For the rest of us, variety is key. Eating the same meal day in and day out not only gets old, but can deprive the body of the array of nutrients it truly needs to succeed in a high intensity training environment.

The other key need for variety, is seasonality.

Buying fresh foods typically results in slightly limited options. If tomatoes aren’t in season, your local grocer might not have tomatoes to sell you, and if you’re on a tomato only diet (first of all, if you are, please, seek help…) you might be out of luck!

Being able to substitute different foods into key food categories, while still preparing yummy, healthy and nutritious meals, goes a long way to keeping you on track for race day!

Training vs race day diet

If you go and do a Google search for "Ironman training nutrition plan" or something of the sort, you'll be flooded with results talking about exactly what to eat on race day. How to calculate the calories you'll burn, how and how often to replenish them, and which supplements are best to do the job.

While that's incredibly useful information, it completely lacks the concept that you need to be eating and fueling well LONG before race day.

There's a big difference between eating to fuel your body through training, and eating to get through a race.

The former involves 3-6 meals a day, weekly meal prepping & whole foods. While the latter involves GU packets, Bonk Breaker bars, electrolyte drink tablets, and other quick, fast acting supplements.

Here, we're going to focus on the food needed to train effectively and get you to race day, but when it comes time to toe the line, make sure you have an on-course nutrition plan as well.

Ok so what, and how much should you eat?

For the purposes of a simplified Ironman nutrition plan, we’re going to focus on 3 main categories of food: carbohydrates, proteins, and (healthy) fats.

One of the simplest methods of ‘macro counting’ and portion control in general, is the 1/2, 1/4, 1/4 rule. Simply said, cover half of your meal plate with carbohydrates (made up of veggies & fruits where possible), 1/4 of your plate with a lean protein (e.g. chicken or fish) and 1/4 of your plate with fat (eg. avocado).

In general, you should feel energized after you eat. Introducing complex carbs (like bread, rice, etc.) will often have the opposite effect on your body, hence the recommendation for whole, lean and unprocessed foods.

You can make small edits to this rule as well though.

  • As you get into higher training volume, you may look to increase your portion of carb slightly (long burning energy source).
  • Just before a race you may increase fat intake for those quicker release energy stores.
  • After a race, you may incorporate more protein to help recover.

Listen to your body, and do what it tells you, but make your adjustments off of a 1/2, 1/4, 1/4 baseline to stay within reason.

Carbohydrates: 1/2 plate

If your body could pick and choose one primary energy source, it would undoubtedly be carbohydrates.

Contrary to popular belief, carbs don’t only come in the form of gluten products (bread, grain, etc.), but also show up frequently in fruits, vegetables and even dairy.

Unfortunately, carbs can also show up in natural (and artificial) sweeteners like sugar, honey, syrup, and other (more obviously unhealthy) items like candy, soda, cookies, etc.

Typically, where you find carbs, you’ll also find fiber. Despite the fact that fiber is a type of carb that you’re body can’t actually digest, it contains several natural benefits.

Fiber that comes from plants, including, but not limited to: vegetables, fruits, nuts & seeds can help prevent stomach or intestinal problems. This is a life saver come race day (trust me), and can help rid you of problems such as constipation (and the opposite of that).

High quality carbohydrates: Sweet potatoes, acorn squash, spaghetti squash, butternut squash, beets, onion, banana, apple, pineapple, peach, quinoa

Processed carbohydrates to avoid: Bread, rice, legumes (peanuts, etc.)

Proteins: 1/4 plate

Proteins are your body’s natural building blocks.

Protein is essential to building and repairing tissue (most importantly in this case, your muscles). They also help fight sickness and infection, serve as excess energy sources, and come in many delicious forms. Most commonly you’ll find your primary protein sources in eggs, poultry, (lean) meat, seafood, and even nuts and seeds.

High quality lean proteins: Chicken breast or thigh, salmon, tilapia

High fat protein to avoid: Red meat (in moderation), sausage, hotdogs

(Healthy) Fats

Like carbs, fats give you energy.

Unlike carbs, fats also help your body absorb key vitamins that it otherwise has trouble acquiring.

There are even some fatty acids that your body needs to survive and thrive, but they’re not produced by your body – you actually have to consume them.

(Healthy) fats come in many forms, some of the most common and popular these days include avocados and coconuts, for example, in addition to some meat, eggs, seeds, etc.

Not all fat is created equal though. Saturated and trans fats can be just as harmful as healthy fats can be good.

  • Saturated fats:
    • Saturated fats are common in butter (duh), beef fat, and even most coconut oils.
    • Common meals high in saturated fats often include: pizza, casseroles, burgers, tacos, and sandwiches – though it obviously depends on preparation as well.
  • Trans fats:
    • Trans fats have become more taboo in recent years, but they’re still found in many popular processed foods available today. Most commonly, you can find high doses of them in some desserts, microwave popcorn, frozen pizza, margarine, and even that delicious coffee creamer you’ve got in the cabinet.

Foods high in trans and saturated fats can often be identified if they’re solid at room temperature. It’s key to athletic performance (and personal health) to limit your intake of saturated fats to less than 10 percent of your calories each day, and try to avoid trans fat all together.

Replace saturated and trans fats with these two types of healthier fats while keeping total fat intake within the recommended range:

High quality fats: Avocados, olive oil, ghee, tahini, chia seeds

Fats to avoid: Large amounts of red meat, butter, coconut oil

Food (and drink) to simply avoid

There are some things that simply have no place in your diet when it comes to training for an Ironman.

Those items, are sugar and alcohol.

As mentioned earlier, if you want a piece of cake and a beer on your birthday, go nuts! But if you’re looking to take your nutrition and training seriously, it’s highly encouraged to limit processed sugar and alcohol intake to as small an amount as you can muster.

Processed sugar

While some sugar is good (like the sugar coming from whole fruit), processed sugar can have some severe and negative effects on the body.

When processed sugar makes it’s way into your bloodstream, your body’s natural reaction is to release insulin.

Insulin is the catalyst by which your blood cells convert sugar into energy (and quickly). While that might be useful in super small, short bursts, your body eventually doesn’t know what to do with the excess sugar left over. Unfortunately, it ends up converting that sugar into fat tissue to store it for later. That fat tissue, results in weight gain (the opposite of what you want when trying to swim, bike or run faster!).

The more sugar is introduced into the body, the higher the resistance your body develops for the insulin created.

This resistance results in a more rapid gain of fat and weight, and in severe cases can result in diabetes.

This won’t happen overnight, but it’s definitely the opposite effect you’re looking to have when devoting your time to training for a triathlon.

With limited to no positive impact, processed sugar should simply be kept as far from your diet as humanly possible.


Simply put, alcohol is a poison that your body tolerates.

When talking about alcohol and athletics, even the acute use of alcohol can have a profound, and negative influence on the body.

Negatively impacting motor skills, the body’s ability to hydrate, your aerobic performance (a key aspect to endurance racing), and recovery, there’s simply no reason to allow a heavy incorporation of alcohol into your diet.

The occasional beer, glass of wine, or cocktail certainly won’t derail your whole training routine, but like anything, keep it in moderation only.

How many times per day should you eat?

Minimum 3, but more like 4-6.

Your day will consist of 3 primary meals (the big ones, breakfast, lunch, dinner), and 2-4  healthy snacks like trailmix (without the candy), avocado, a bowl of fruit, oats, etc.

For the big meals, follow the 1/2, 1/4, 1/4 rule mentioned above, and for the smaller meals/snacks, get a little more of what you need based on your training.

As mentioned previously, if you’re in heavy volume mode, find a way to grab some extra carbs (half a sweet potato for example), or if you’re coming up on a race or workout, maybe some extra healthy fats. Lastly, it’s a good idea to incorporate a little protein too to supplement recovery. Something like a hardboiled egg works nicely for that “snack on the go”.

The best triathlon nutrition products & supplements

There are dozens, hundreds, even thousands of endurance supplements out there in the market that promise things like increased VO2, less fatigue, and more.

It's important to remember that many of these supplements aren't backed by the FDA and aren't legally obligated to release every ingredient within them. So with that in mind, you can take them at your own risk.

There are, however, a few supplements for triathletes worth exploring. These supplements come in the form of protein powder, and electrolyte tabs.

Protein powder

There are hundreds of protein powders out there. Some are made of egg protein, others fish, others beef. Some are “whey” others are not, and the list of “this or that” goes on and on.

Many protein powders commonly found, contain gluten in some way. So for those of you on a Paleo, Keto, or otherwise gluten-free(ish) diet, you may want to be wary of such products.

The product recommended to (and by) most of the athletes we work with here, is a protein product from SFH called “Fuel”.

Fuel is gluten free, soy free, non-GMO, rBST free, and certified in all of those things by the NSF (National Science Foundation).

While SFH makes a more “standard” protein powder, Fuel comes up often because of the added MCT (healthy fat), carbs and fiber, not found in traditional protein powder. In that regard, it’s a “3-in-1”, full of nutrients needed for a complete triathlon nutrition plan.


In addition to getting nutrients from food and eating several, healthy and balanced meals throughout the day, the other thing triathletes do more than most, is drink fluid.

While water is incredibly important, critical, and non-negotiable, it’s often not enough to replenish the nutrients lost by the body during training.

Products like Gatorade were the first to call this out decades ago when they were first introduced to the public.

The thing to consider with many sports drinks though, is the amount of “extra” stuff often found in them that the body doesn’t need.

We’ve gone in depth about the dangers of processed sugar already (especially as it pertains to your training), so it’s best to look for an electrolyte supplement that limits the added sugar, and maximizes things like sodium, potassium, magnesium & calcium. It doesn’t have to be 0 sugar, but less than 1-2g is deal.

Personally, I used Nuun, but I have known people to use (and love equally as much) GU tabs. Both of which meet the requirements listed above.

WOW, that's a lot... where do you even start?

Now you have the information. Eat whole foods, 1/2, 1/4, 1/4 plates, avoid sugars, eat healthy fats, etc. etc.

Despite knowing all of that though, it can still be paralyzing to figure out exactly where to begin.

Meal prepping

The beauty of focusing your food around carbs, fats and proteins, is there are hundreds of “mix and match” combinations to keep your meals interesting.

That also helps when preparing meals in bulk, because let’s be honest, the one thing that people training for an Ironman don’t have, is extra time on their hands.

Let’s take, for example, 2 meals:

  • Meal 1:
    • Shredded chicken breast (2lbs)
    • Broccoli (2 heads)
    • 2 large sweet potatoes
    • Paleo ranch and franks hot sauce (if desired)
  • Meal 2: Fajitas
    • Shredded chicken breast (2lbs)
    • Green & red bell peppers (1-2 each)
    • Cauliflower rice (1lb)
    • Lettuce wraps (you can pick 1 head of iceberg lettuce apart)

The reusable in this example is the shredded chicken. For both recipes, you can get a ‘family pack’ of chicken breast (say ~3-5lbs) and cook it in the crockpot (low for 6-8 hours is best).

Pro tip: The secret, by the way, for perfectly shredded chicken is to place the chicken in the crockpot and smear it with a tablespoon of ghee. Then add chicken stock, salt and pepper until the chicken is submerged. After 6-8 hours, it’s juicy and just falls apart!

While your chicken is cooking, you can blanch a few heads of broccoli, roast sweet potato halves (400 degrees ~50min is usually good), sauté bell peppers and fry up some cauliflower rice, all pretty much at the same time. I’d probably order it like this:

  1. Get the chicken in the crockpot & cooking
  2. Pre-heat the oven while chopping broccoli & boiling water
  3. Add sweet potatoes to the oven
  4. Chop the bell peppers
  5. Add broccoli to the boiling water
  6. Sauté the bell peppers & fry the cauliflower rice

When the food begins to finish cooking (starting with the rice, bell peppers, and broccoli likely in this case), you can start to divide that food into containers. You can find nifty containers that follow the 1/2, 1/4, 1/4 rations so there’s less thinking involved, though using your eye works just fine too.

All that’s left to do is wait for the sweet potatoes and chicken to be done, add it to your containers and you’ve got 4-6 meals already done!

Even in these 2 examples, for variety you can swap the chicken for lean beef or fish, broccoli for asparagus, green beans, cucumber salad, and the sweet potato for (basically any kind of) squash, cauliflower rice, etc.

Just by starting with a basic formula, and finding new ways to incorporate a new protein, carb or fat, you’ve got access to an endless variety of meals, all of which can be cooked and shopped for in bulk, saving you time (and $$) during training.

Now you know what to do, but will you actually do it?

We’ve all been there before.

We do the research, we lay out the plan, and we get super motivated! But then, we don’t follow through.

For one reason or another, we find an excuse not to start a new routine, or fully buy into something new.

One of the primary reasons for this, is a lack of accountability to anything or anyone else outside of your own mind.

If nobody knows you’re trying to change your eating habits, they can’t possibly give you a hard time for not following through, right? And if you don’t have a mechanism forcing you to log, keep track, or otherwise face the facts of if you are or are not following through yourself, it’s easy to fall back to an old routine.

So let’s talk about two awesome ways to hold yourself accountable. One is social in nature, and the other, private.

Food journaling

There are plenty of methods in which to document your food intake, but regardless of which you use, two main rules apply: be honest, and be comprehensive.

Whether you’re using a notebook, or an app like My Fitness Pal to log your food, make sure that if you sneak a Snickers, you log it, and at the same token, if you eat perfectly and you’re super proud of what you’ve done, log that too!

Notebooks are useful, but I’d recommend an app such as MFP because it will also keep track of your calorie intake, and more importantly, the breakdown of carb, fat and protein based on your inputs.

This way, you can make adjustments as needed in order to follow the 1/2, 1/4, 1/4 rule a bit more closely.

There’s immense power in having to write down what you eat. It makes for an interesting monologue when staring into the snack cabinet going “I really want those M&M’s, but then I’d have to log it.. and I’ve got a pretty good streak going, I wouldn’t want to ruin that!”.

You’ll be surprised what an impact getting on a little roll can have!

Share your goals with the world

Chances are, if you’re out there researching an Ironman nutrition plan, you’ve likely either signed up for an Ironman, or are seriously considering it.

Whether its the Ironman race itself, some other triathlon, or committing to a nutrition change, it’s important for you to consider sharing your goals with the world. And if not the whole world, at least your close friends and family.

If they know you’re about to embark on such a journey, and you’re serious about taking your diet and fitness to a new level, they’ll no doubt support you! At the same time, they’ll also help hold you accountable to the goals you’ve shared with them.

When signing up for my first Ironman, the scariest part of the whole process was putting out on Facebook that I’d signed up! I was in no way, shape or form confident in my ability to finish the race (at least not yet), but I knew that putting it out there in the world, would make my commitment that much more real.

The support received was second to none, and looking back, there’s no way I cross that finish line without the help of my friends and family keeping me on track!

There you have it, a simplified Ironman nutrition plan

There are plenty of articles out there that will help you calculate (to the half gram) how much of each macro and micro nutrient you should be consuming.

For most of us though, we just need guidelines and flexibility. A triathlon nutrition guide that we can follow without sacrificing flavor, variety, and ultimately, freedom.

So remember, eat whole foods, mix up what you eat, and allow yourself to cheat every once in a while (it won’t kill you!). Just keep a close eye on what you’re doing, and share it with those around you.

You’ll be surprised just how easy it is to fuel your body to perform at it’s best come race day!