The Triathlete’s Guide To Diet And Nutrition


Triathletes need to be very skilled in three separate sporting disciplines. That requires plenty of training and a lot of dedication.

But the other part of being a good triathlete is diet and nutrition. You can be highly talented in all your sports, but if your diet isn’t right, you’ll never reach your full potential.

Not sure how to use your diet to your advantage? Today we’re discussing the triathlete’s guide to diet and nutrition, so you can start using your fuel as a tool.

Tips for Getting Your Diet and Nutrition on Track

Your diet and nutrition can be some of the most tricky things to get right. And yet, it can be one of the first things to ruin your performance!

Here are our top tips for getting your diet and nutrition on track so you can start using it as a performance-enhancing tool.

1. Have a Plan

Planning is already half the battle won. Take some time to really examine your diet and pay attention to weak spots that need to be improved.

Once you’ve found where you need to improve, come up with a plan for improving it. It’s not as hard as it sounds, either. If you fall short in the evenings when your sweet tooth kicks in, try to find low-calorie sweet things that you can snack on at night.

Or maybe your weakness is coffee (and the large amounts of sugar and cream that come with it). If you don’t want to give up coffee entirely, plan for how to lower your intake of sugar and cream, like using a zero-calorie sweetener.

In fact, we advise planning out your full week’s worth of meals. This makes it super easy for you to stick to calorie counts, hit all the necessary macronutrients (more about this later), and not have to think about what to cook on a day.

2. Keep It Real

By this, we mean avoid processed foods! Now, there’s nothing wrong with a donut here and there. But we highly advise sticking to whole, natural foods as much as possible.

It isn’t hard. Avoid pre-prepared microwave meals, pre-marinated meat, and junk food. You can still eat great food if you buy ingredients and make healthy meals at home.

Choose whole foods like vegetables, lean meat, pasta, and rice. Healthy snacks like fruits, nuts, and seeds are ideal.

If you are going to stray, remember the 80/20 rule. 80% whole, real foods and 20% cheat foods is an acceptable ratio.

3. Know Your Carbs

This is where most people go wrong with whole foods. Processed carbs often contain a skewed calorie/nutritional value ratio. By that, we mean that they’re high in calories but low in nutritional value.

Avoid processed carbs like bread, breakfast cereals, candy bars, and sodas. Choose healthy, easy-to-digest carbs that are whole foods.

It’s also worth doing some research on simple vs complex carbohydrates, and how they affect blood sugar. Simple carbs break down quickly and provide short-term energy. Complex carbs take longer to break down and provide more sustained energy.

Understanding this can help you decide which carbs to eat, and when, for the best performance.

4. Find the Good Fats

Fat is not the enemy! Healthy fats have many benefits, including nourishing the hair and skin and keeping the brain sharp.

But there are unhealthy fats too, which should be avoided. Partially hydrogenated oils and saturated fats in processed foods are unhealthy and can have a negative effect on your body.

If you’re eating whole foods and cooking with olive or coconut oil, you’ll mostly be ingesting healthy fats.

5. Seek Balance

This is where the 80/20 rule comes in. There’s no need to restrict yourself completely from all of the foods you love.

Try to eat great, healthy stuff 80% of the time. The other 20%, you can “cheat”. That may mean a small cheat snack every day, or a larger cheat meal once a week.

As long as the majority of your eating is whole, healthy foods, you can afford to have a cheat snack every now and then. In fact, it’s encouraged! It gives you something to look forward to.

6. Carb Loading

Increasing the amount of healthy carbs in the few days before your race could be beneficial. This allows your muscles to build up a great store of glucose to use on-the-go.

Carbo loading doesn’t just mean going wild on the pasta and donuts, though. There’s a right way to do it and a wrong way to do it. Check out this article if you’re interested in carbo-loading so you can make sure you do it properly and reap the benefits.

7. Supplements

Supplementing with nutrients that are hard to find in whole foods could be helpful too. Make sure they’re all-natural and healthy too.

Caffeine is a good choice for an energy boost. Protein powder may be worthwhile if you struggle to get enough protein in through meat.

Beetroot juice is another supplement that’s low in calories and high in nutrients. Make sure it’s as natural as possible and doesn’t contain much sugar or processed ingredients.

Lastly, beta-alanine is worth trying. It helps the body produce carnosine, which is a compound that improves muscle endurance during high-intensity exercise.

Monitor Your Macros

Eating healthy is one thing, but making sure you’re hitting your macros is another. Macronutrients include carbohydrates, protein, and fats. Each one serves its own purpose.

Carbs are the body’s main source of easy-access energy. Protein helps muscles to rebuild, repair, and grow after exercise. Fats keep you full and promote brain health.

How to Calculate Your Macros

First, you’ll need to know how many calories you should be eating on any given day. This article explains how to find your ideal calorie intake for your goals.

In order to determine your macros, you’ll need to decide what percentage of each you’re going to aim for. A good choice is 50% carbs, 25% protein, and 25% fat. You can change this as you wish.

Let’s assume an adult runner eats 2500 calories a day and splits it according to the ratio above. Here’s how you would calculate your macros.

Multiply your total calories by each percentage to get your calories.

Carbs: 2500 x 0.50 = 1250 calories worth of carbs
Protein: 2500 x 0.25 = 625 calories worth of protein
Fats: 2500 x 0.25 = 625 calories worth of fats

Then, simply work your daily food intake around these. If doing the math is a bit much for you, you can use calorie/macro calculators like this one, and track your food using an app like MyFitnessPal.

Tips for Eating for Training

Carbohydrates to Fuel Energy

If you aren’t following macros as we’ve just calculated above, aim for between 5 and 10 grams of carbs per kilogram of body weight (remember, one kilogram equals 2.2 pounds) on training days.

Make sure the carb sources you choose are mostly whole, healthy food sources.

Lean Protein

Your protein requirements while training will range from about 1.2 to 2 grams of protein per kilogram of bodyweight.

It should consist of lean protein sources like poultry, fish, lean beef, and eggs. Many legumes and some other vegetables also contain small amounts of protein.

Try not to eat your entire day’s protein at once. Spread it over the day, but make sure to eat a good bit of protein after an intense training session to help the muscles recover.

Fats – Nuts, Seeds, and Fish

Fats should make up the rest of your daily calories. Nuts, seeds, avocado, fish oil, and healthy cooking fats like olive oil and coconut oil should make up this total.

What to Eat Before a Workout (2-3h prior)

We’ve just mentioned that you should eat protein after a workout, but what should you eat before you work out? Protein before a workout is also a good idea, as are some carbs to give you energy.

Depending on the time of day you work out, try:

  • Whole-grain toast with nut butter and a banana.
  • Oats, protein powder, and berries.
  • Scrambled eggs with vegetables.
  • A smoothie with a scoop of protein powder.
  • Roasted chicken, rice, and vegetables.

Tips for Eating for a Race Week

In the 2 to 3 Days Before Your Event

Now is the time to carbo-load if you want to. Instead of the recommended 5 to 10 grams per kilogram, these days you should increase it to between 10 and 12 grams per kilogram. Keep it up for a day or two before your race, but try not to have a large meal the night before your race.

On Race Day

Have a light meal on the morning of your race. You don’t want to eat a lot and feel weighed down. Between one and four hours before your race begins, you should consume about 4 grams per kg bodyweight of carbs to fuel you for the start of the race.

Avoid high-fiber foods as they can cause gastrointestinal distress. You can add a bit of protein to the mix if you want to, but protein is usually very satiating and may make you feel too full.

Recovery Nutrients

Within an hour of completing your event, consume about 1 to 1.2 grams of carbs per kilo of bodyweight. Protein is essential after your event to give your muscles a recovery boost.

When/What Time You Eat Matters, & What Macronutrients You Eat

Eat Early

Front-loading your daily calorie total can help. Have a large breakfast to fuel you throughout the day.

You’ll need to be disciplined with the rest of your day’s food, but if you have a hearty and healthy breakfast consisting of whole foods, you should be full for a good few hours.

Eat Often

Snack! The key is to choose healthy and low-calorie snacks. Frequent snacking helps keep your blood glucose levels stable throughout the day. It also stops you from getting ravenous and overeating at your main meals.

Try things like:

  • Cherry tomatoes, cucumber sticks, and carrot sticks with a low-calorie dip
  • A handful of nuts of your choice, preferably non-salted
  • A piece of fruit (fresh, not dried fruit)
  • Bake some protein muffins
  • Energy bars (be choosy – they’re not all equal)
  • A protein shake

Eat Before Exercise

A healthy meal containing around 100 grams of carbs should be eaten 3 to 4 hours before you exercise. By the time you begin working out, those carbs will be ready to transform into energy to push you through.

Fuel During Exercise

If you’re training for an hour or longer, you should be taking in 30 to 60 grams of carbs per hour. You can use an energy gel or energy chew for the easiest and most accessible form of quick energy while you’re training.

They’re also small, inconspicuous, and very easy to carry with you, whether you’re running or on the bike.

Eat After Exercise

For the best post-exercise, recovery-promoting meal, aim to eat about 0.25 grams of carbs per kilogram, and around a quarter of that total in protein.

This combination will replenish your energy and give your muscles the necessary protein for repairing and recovering.

Our Thoughts on Different Types of Diets

The Keto Diet

The Keto diet is a popular one, and it involves cutting out carbs as much as possible and increasing your fat intake. The idea behind this is to train your body into burning fat for fuel instead of carbs.


When following the Keto diet, you don’t have to eat low-fat stuff anymore! You’re free to eat all the cheese, fatty red meats, nut butters, nuts, and full-fat dairy products. And you can eat them in good large amounts, too!

The Keto diet has also been documented to help people with seizure-related conditions. Healthy fat is a neuroprotector, so it can assist in healing brain traumas and just keeping the brain healthy.

It can also help to improve mental performance during exercise. Because it’s a brain cell healer, it can spark your cells to focus better while you’re busy working out, aiding in the mind/muscle connection.

Generally, as long as you make sure to stick to your calories, you can also lose weight fairly easily on the Keto diet. In the beginning, you’ll find that the increase in fat keeps you feeling full, so you aren’t tempted to snack on unhealthy foods and overeat.


The hardest part of the Keto diet is keeping it up long-term. Many find it difficult to restrict carbs for extended periods of time. Part of this is that you’re not necessarily getting all the nutrients you need from a high-fat, low-carb diet.

It can also be tempting to fill up your fat quota with unhealthy fats. This can lead to cardiovascular disease.

Excess fat in your diet could also lead to a sensitive stomach! Not to mention that cravings for carbs could become intense, which often leads to binging on unhealthy stuff.

Paleo Diet

The Paleo diet is all about only consuming whole foods that your ancestors would have eaten. It includes meat, fish, veggies, fruits, nuts, seeds, and so on.

Because it’s based on an ancient way of eating, hardcore Paleo followers won’t be allowed to eat things like dairy, legumes, grains, sugar, salt, coffee, alcohol, and anything that exists as a result of agriculture.

Less hardcore followers may simply choose to forgo processed foods and stick to whole, natural items, even if they have been cultivated.


It’s all about nutrient-dense, high-quality, all-natural foods. This keeps you away from unhealthy processed foods and keeps your blood glucose levels stable.


Eliminating foods like grain and legumes can restrict carbohydrate sources and make it difficult for athletes to get enough carbs in.

High-Carbohydrate Diet/Carb-Loading

As its name suggests, this diet is all about eating high-carbohydrate food sources, which give you plenty of energy.


A high-carb diet gives your muscles a quick and easy source of fuel. Glucose stored in your muscles will be easily accessible for races, and you’ll find it easy to consume gels and liquids during races.


Over time, a high intake of carbs can be detrimental, especially for those who struggle with diabetes. Too many carbs can spike blood sugar levels, leading to problems like obesity and insulin resistance.

An increased carb intake also means an increased fiber intake. If you aren’t used to it, this can lead to digestive troubles.

Vegan/Vegetarian Diet

Vegetarians don’t consume meat, fish, poultry, or dairy products. Vegans don’t consume anything that’s derived from animals, including the above plus things like cheese, butter, honey, and gelatin.


These kinds of diets can help to reduce the risk of a variety of health conditions. This includes cancer, heart disease, and diabetes.

More fruits and vegetables give you more antioxidants, which equals a stronger immune system.


Vegans and vegetarians are at risk of vitamin and mineral deficiencies. Meat and animal products offer amino acids and certain vitamins and minerals that are hard to get enough of when eating only plant-based foods.

You may need to resort to supplements to get enough zinc, calcium, iron, vitamin D, vitamin B12, and DHA (a fatty acid found in fish oil).

It can also be difficult to eat enough calories when you’re on a vegan or vegetarian diet. When you’re training hard, your body needs a certain amount of fuel, and although vegetables and fruits are nutrient-dense and filling, it can sometimes be hard to eat enough of them to fulfill your body’s energy needs.

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Shanna is a writer who runs... And cycles, jumps rope, and lifts weights. She lives in beautiful South Africa and enjoys sharing her knowledge and experience with other avid athletes.