Nutrition for Triathletes: Building Your Triathlon Nutrition Plan

Nutrition is called the 4th discipline of triathlon for a reason, it can make or break your training and racing. If you want to reap the reward of all that swim, bike and run training, you need to ensure you have the right fuel to train and compete. A triathlete’s diet should be optimized to ensure key nutrients, and supplements for triathletes are consumed to maximize training and racing. In this article we’re going to walk you through creating your winning triathlon nutrition plan. We’ll walk you through important nutrients for triathletes, and how to consume them pre, during and post training. We’ll also discuss hydration and electrolyte balance as this is a critical component of your triathlon nutrition plan.

Why Is Nutrition Important for Triathlon?

Nutrition is critical to triathlon success, both in training and in racing. When we exercise for more than 90 minutes continuously, our bodies need fuel to stay energized. In addition to fuel, we need to hydrate for even shorter workouts, especially in hot weather. In addition to fueling workouts, nutrition is important for our overall health and wellbeing. Let’s explore the key nutrients that are critical to a triathlete’s diet.

What Should I Eat for Triathlon? – Important Nutrients For Triathletes


We have a love hate relationship with carbohydrates (carbs). While popular diet culture would have you believe that carbs are the enemy, they are essential to a triathlete and you should be consuming them at most meals and snacks. When we start to swim, run or bike, we first use up the carbohydrates in our blood stream (glucose), and then deplete our liver’s stores of carbohydrates (glycogen) after about 90 minutes of activity.  

First, let’s look at overall daily requirements. For athletes engaging in moderate training (1h/day, e.g., training for a beginner or sprint triathlon) it’s recommended to get 5-7 grams per kilogram body weight per day. For moderate to high intensity training (1-3 h/day, e.g.,  training for an olympic or half ironman) it’s recommended to get 6-10g/kg/day. Ultra-endurance athletes training (4-5h/day, e.g., ironman training) may need up to 8-12g/kg/day (1). So how do we know if we’re getting enough? Working with a sports dietitian is the best way to determine this, but if you want to DIY, you can use an app such as My Fitness Pal* for 2-3 days and check your numbers.

If you are hitting the minimums for your ranges based on activity level, and feel energized and don’t have excessive fatigue, hunger, or cravings, that’s a good indicator that you are in the right place. We’ll cover more about the timing of carbohydrate intake during the pre, during and recovery nutrition sections below. 

*If you have any history of disordered eating behaviors I would not suggest using a tracking app as these may trigger dieting behavior. Instead work with a sports dietitian.

Carbohydrate content of some common foods**:

Bread: 15g/slice

Pasta 1 cup cooked 40g

Rice 1 cup cooked 45g

Banana 1 medium 27g

Sports drink 1 cup 15g


Protein is essential for muscle growth and repair as well as for other functions in the body. It also helps with controlling hunger and is an important part of a triathlete’s diet. Athletes should aim for 1.2-2.0g/kg per day spread out through meals and snacks (approximately 0.3g/kg every 3-5 hours) (1). To put this in perspective, for a 150lb person this looks like having 20g every 3-5 hours. 

You should aim for a variety of sources of protein to ensure a good mix of amino acids that different proteins contain. This is especially important if you are predominately consuming plant based proteins. We’ll cover more on protein for post-exercise recovery in the recovery nutrition section.

Protein content of some common foods**:

Chicken breast 1 small 37g 

Lentils 1 cup 18g

Milk 1 cup 8g

Greek yogurt 1 cup 23g

Fish, tuna 1 can 41g

Peanut butter 2 tbsp 7g

** check product nutrition facts for most accurate nutrient amounts


Although not typically a focus of sports nutrition, fat plays an important part of the overall athlete diet. Athletes are typically advised to follow the fat intake guidelines of the general population, and there is not usually any need to track fat intake. Diets that are too low in fat can lack essential fatty acids and fat soluble vitamins, so it’s important to ensure fats are part of most meals and snacks. This isn’t usually challenging as many protein-rich foods also contain fat (e.g., nuts and seeds, dairy products and meats).

What Should I Eat Before a Triathlon?

We’ve all found ourselves in the middle of a run feeling like “why did I eat that before this run?”. Or you’ve felt tired and a bit hungry and just low energy while out on the bike. What you eat before training has an impact on how you feel as well as the energy you have for your workouts. Let’s break it down into pre-training and pre-race as the approaches can be slightly different.


Eating before workouts takes practice and trial and error to find what will work for you and your gut. It’s a balance between feeling energized and not feeling like you have food sitting in your stomach and being uncomfortable. Aim for a meal or snack with 1-4g/kg carbohydrates in the 1-4 hours before a workout. This can include a small balanced meal 2-4 hours before and then a quick boost of carbohydrate right before training (e.g., a gel, ½ a banana, some watermelon. You’ll want to watch how much fiber, fat (greasy meals), spicey, gassy foods (e.g. raw veggies like broccoli) you include in these meals, as too much of any of these can slow down digestion or give you bloating. 

It’s a good idea through testing and learning to find a few meals and snacks that work for you. Examples of before workout meals include: cereal with fruit and nuts, toast with peanut butter and banana, a sandwich with lean meat and veggies, or a small bowl of pasta with tomato sauce and cheese.


It’s important to replicate the foods you eat in training for race day. You don’t want to try anything new on race day whenever possible, as you don’t know how your body will react. 

If your event is longer than 90 minutes you may benefit from carbohydrate loading the 36-48 hours prior to your race. Carbohydrate loading consists of consuming a very high amount of carbs (10-12 g/kg) on the day (or two) prior to your event, with the goal of supercharging your muscle glycogen stores. Some things to note about carbohydrate loading:

  1. You’ll want to drink plenty of water or carbohydrate-containing fluids to aid with the digestion of the increased intake.
  2. Contrary to general health eating advice to eat whole grains and high fiber foods, this is one time you’ll want to look for lower fiber “white” food options. If you try to load with high fiber foods you’ll likely experience bloating and gas due to excessive fiber intake.
  3. Eating protein and fats that are part of carbohydrate meals is still important but the main focus is on getting enough carbohydrates.

Like any race nutrition strategy, you’ll want to experiment with carbohydrate loading in any race-simulation workouts, or less important races, so you can see how your body and gut reacts to this approach.

Whether you have carbohydrate loaded or not, you’ll still want to consume a pre-race carbohydrate-rich meal the day of your event, 1-4 hours before and a top up ~30 minutes prior to the start. The ideas in the pre-training section above can work well for race day as long as you’ve tried and tested them.

What Should I Eat During a Triathlon?

Fueling during triathlons is especially important for training sessions or races longer than 60-90 minutes. When it comes to triathlon distances, I would suggest fueling for a sprint triathlon but especially Olympic or longer distances. The focus of your fueling plan should be on carbohydrates, fluids and sodium.

After about 90 minutes of continuous activity, we deplete our body’s stored carbohydrates. This means that if we want to continue to have a steady stream of blood sugar (glucose) we need to take in carbohydrates. If we continue on and fail to consume carbohydrates, we experience fatigue and fogginess which is often referred to as “bonking”. For activities lasting 1-2.5 hours, 30-60g/hour is recommended. If the planned training will be >2.5 hours, then 60-90 g/hour is recommended (as tolerated). The “as tolerated” part is important, just like training your body, you need to train your gut to be able to handle carbohydrates while exercising. Start with the lower end of the range and train your gut to be able to take in higher amounts with practice. 

Typically taking in fuel on the bike is easier than the run but you’ll need to practice both. Choosing products that have a mix of carb sources (e.g., glucose and fructose combinations like sport supplement products) can allow for more tolerance of higher amounts. You can use a combination of sport supplement products (sport drinks, gels and bars) and real food. Keep in mind when you are racing or training harder, liquid and gel options may be easier to absorb than solid foods that require more digestion. You’ll want to go easy on fiber, fat and protein rich foods when training as they will be slower to digest.

When it comes to hydration, our fluid needs are highly personal. A good starting point is aiming to consume 400-800mL per hour but you could need less or more than this. The amount you need can vary based on your sweat rate, temperature and other factors. If you haven’t completed a sweat test, you should consider doing one but remember that you’ll want to repeat these over time in different temperatures, as the fluid needs can vary substantially with different weather conditions.

In addition to water for hydration, we need to consider that we lose sodium in our sweat. The amount of sodium we lose in sweat is highly variable. If you have a high sweat rate or are a salty sweater chances are you’ll need to add sodium to your training fuel plan, especially if you are training or racing for more than 2 hours. Start with aiming to consume 300-600 mg/hour and adjust as needed. You can do this through electrolyte drinks (which also help you get your carbohydrates) or sodium tablets or other high sodium endurance sport supplements. 

What Should I Eat After a Triathlon?

When it comes to recovery, nutrition is a critical aspect of your training. Our nutrient focus for the recovery period is protein, carbohydrates and fluids. It’s important to include 0.3 g/kg (about 18-25g) of protein in your recovery snack or meal and consume this within 2 hours (the sooner the better). 

Carbohydrates are also an important nutrient for recovery, especially if you are training at an intense level and depleting glycogen stores. It’s also even more important when you have another training session coming up in less than 24 hours that you need to refuel for. As part of your daily overall carbohydrate intake discussed above, you should aim to consume 1-1.2g/kg/hour of carbohydrate in the 3-5 hours post training to accelerate muscle glycogen replenishment.

When it comes to fluid replacement, drinking 1.5 times what was lost in training can help with rehydration, and adding some sodium to the recovery food or fluids may be necessary if larger sweat sodium losses occurred, to help absorb the fluid. Good recovery foods include smoothies, Greek yogurt parfaits or cereal with milk, fruit and nuts or seeds for additional protein.

Mastering your triathlon nutrition plan can seem overwhelming but it doesn’t have to be. Focus on the key nutrients for triathletes for your day-to-day eating, and then practice your pre, during and recovery nutrition strategies in training to help fuel and recover optimally from your workouts.


2 thoughts on “Nutrition for Triathletes: Building Your Triathlon Nutrition Plan”

Leave a Comment

Your email address will not be published. Required fields are marked *