Complete Triathlon Diet & Nutrition Guide For All Abilities

by Zach Nehr

Blog ▸ Complete Triathlon Diet & Nutrition Guide For All Abilities

Triathlon Diet 

When it comes to training and racing, the triathlon diet plays a massive role in your success. Once you have nailed down the fundamentals of swimming, biking, and running, it’s time to tackle the fourth leg – nutrition! 

What you eat significantly impacts your performance; nutrition can be the difference between a personal best time and not even making it to the finish line. 

This post will teach you what to eat to get the most out of your body. We’ll do an overview of some of the key nutrition pillars you will need to get your triathlon diet right if you’re looking to enjoy a long and healthy career as a triathlete, runner, swimmer, or cyclist. 

We are going to cover:

  • The triathlon diet, in general
  • The types of foods you need to eat on a day-to-day basis
  • An example meal plan
  • What to eat before triathlon training
  • What to eat during triathlon training
  • What to eat to recover after training
  • Your race day nutrition strategy
  • How many calories do you need to eat?
  • What nutrition supplements to consider

The Triathlon Diet

Triathlon diet

As a triathlete, you must train for not one but three different sports weekly. Fueling and recovery are key to adapting to your training and ultimately getting fitter and faster.

Triathlon is an endurance sport. The further and faster we go, the more fuel we burn. So it’s time to decide what type of high-performance machine you’re driving and what type of fuel you’re putting into it. 

As a triathlete, you should focus on building a baseline healthy diet from all food groups: wholegrain bread and cereals, fresh fruit, salad and vegetables, lean meats and meat alternatives, dairy, legumes, healthy oils, nuts, and seeds.  

Then you’ll layer in the more advanced sports nutrition principles to enhance fuelling and recovery.

Carbohydrates for the Triathlon Diet

Carbohydrate is the primary source of fuel. The more you exercise, the more you need.

Five main food groups provide carbohydrates in our diet:

  • Bread and cereals (breakfast cereals, pasta, rice, noodles, muesli bars, flour, etc.)
  • Fruit (fresh, frozen, juice, dried)
  • Dairy (milk, yogurt, custard)
  • Legumes (red kidney beans, lentils, chickpeas, etc.)
  • Starchy Vegetables (potato, sweet potato, corn, etc.)

How many carbohydrates you need is individual to you and your needs. I firmly believe that you shouldn’t eat the same thing each day; instead, periodize your carbohydrate intake to match the training you’re doing.

The purpose of periodizing your carbohydrate intake is twofold:

  1. Ensure you are fueling and recovering properly: give the body what it needs!
  2. Match your overall intake to what’s required: your nutrition should enhance your training!

For example, suppose you were to periodize your carbohydrate intake to match your training needs. In that case, you may only consume 150 grams of carbohydrate on a recovery day. Still, you’d consume 400g of carbohydrates on a big weekend training day. 

Of course, this is a general number and is very different for every person, but this gives you a rough idea of the range of carbohydrates you might consume on different days to implement periodization.

“Fuel for the work required. Your carbohydrate needs will change daily depending on what type of training you’re doing.”

Protein for the Triathlon Diet

Protein is the building block that helps with muscle recovery and repair. Rich sources of protein in our diet come from:

  • Animal meats and poultry
  • Fish and seafood
  • Dairy
  • Legumes
  • Nuts & seeds
  • Eggs
  • Tofu, tempeh, and other vegetarian alternatives 

Our protein needs are like a cup; we must fill it regularly throughout the day. Be careful not to overfill it at some meals while underfilling it at others. Protein is also vital in the recovery window after exercise. 

Some general guidelines on protein for a triathlete diet:

  • Target 50-250 grams of protein per day depending on your needs (heavier athletes and heavy training loads with strength training sessions will require more protein than lighter athletes or more sedentary athletes)
  • Target 20-40 grams of protein after workouts for recovery

Fats for the Triathlon Diet

Dietary fat is essential for life: without fat, we would die. But some fats are healthier for us than others.

We should include more monounsaturated and polyunsaturated fats for a healthy balanced diet and limit saturated fats. 

Healthy fats to consume in your diet include:

  • Avocado
  • Nuts & seeds
  • Extra virgin olive oil
  • Fatty fish – Salmon, tuna, herring, mackerel 

Macronutrient Breakdown

How much you need of each of the macronutrients depends on your specific needs. There is no one-size-fits-all with nutrition. What might work for your training buddy may not work for you.

As a starting point, you could compare what you’re currently doing to the figures below:

  • Carbohydrates 45-65%
  • Protein: 25-35%
  • Fat 20-30%

But, know there are limitations to counting calories and tracking everything you eat in an app.

Example day of eating for a moderate triathlon training day

Training session 1

60-minute run under Zone 2 HR ceiling


Natural muesli, high-protein yogurt, and fresh fruit

Morning Snack

Wholegrain crackers and cottage cheese

Milky coffee


Large wholegrain wrap, a lean protein source (chicken, beef, tofu, tinned fish), salad, and avocado

Afternoon Snack

Fresh fruit and a handful of raw unsalted nuts to fuel up for higher intensity evening session

Training Session 2

3.5km moderate to hard pool swim with intervals


Mexican mince bowl with corn tortillas that ticks your individual recovery targets 

Supper/pre-bed top-up snack 

Yogurt and fresh or frozen berries 

Notice how we perform the first low-intensity session fasted to promote fat-burning abilities; this technique is used for experienced athletes who aren’t at risk of a significant calorie deficit. More carbohydrates bookend the more intense swim later in the day because it’s a hard effort. This is an example of the concept of nutrition periodization.

Of course, this is a general example. Your individual needs will vary based on weight, gender, training program, level of experience, and body composition goals. You should seek help from a triathlon nutrition sports dietitian to understand what you need specifically for you and develop a plan that fits in with your lifestyle. 

I offer many free dietitian-approved triathlon diet plan recipes here on my website to help you get started.

How many calories do you need?

It depends. Everyone’s daily energy needs are different. Generally speaking:

  • The more training volume you do, the more calories you will need. 
  • The larger you are, the more calories you’ll need
  • The more lean muscle mass you have, the more calories you’ll need
  • The less food your digestive system can extract, the more calories you’ll need

You can see that the amount of calories you need is a complex formula and depends on many factors.

Counting calories is not productive when you are a triathlete. Calorie counting has many limitations. At the end of the day, your precious time is better spent on mobility or getting organized with your meals for the day ahead. 

Rather than count calories, it would be best to experiment with how many calories you need to lose, maintain, or gain weight. The number of calories needed is different for every single person, and counting calories without a solid understanding of the advantages and drawbacks of doing so might not get you the desired results. 

Even if it’s temporary, we recommend that people work with a qualified sports dietitian with a background in working with endurance athletes. Once you have the foundations of your day-to-day diet, it’s time to focus on your training nutrition. Because what you do before, during, and after your training has the most significant impact.

Pre-Training Nutrition

The type of workout you’re fuelling for will dictate what to eat (or not eat) before training. If you’re new to the sport, try to have something small and easy to digest before training because you will have higher needs than a well-trained athlete.

Focus on carbohydrate-rich foods that are lower in fiber. This will ensure you digest it quickly and it doesn’t come back to “haunt” you later in your session (i.e., digestive problems).

Some examples of what’s to eat before running or triathlon:

  • Banana
  • Dates
  • Toast with spread
  • Muesli bar
  • Liquid meal 

During training nutrition

Consider your duel and hydration needs depending on how long you’re training for.

  • Workouts less than 90 minutes: water without electrolytes should be sufficient as you can eat before and after that session
  • Workouts longer than 90 minutes: Fuelling with carbohydrates and electrolytes is required. The longer and faster you go, the more fuel you will need. 
  • Workouts endurance workouts longer than 2 hours: Fuel and fluid will be essential to surviving and adapting to the session 

The calculator below will give you a rough starting point for how many calories you need for each workout. As always, this calculation is a general guideline and not customized advice that’s certain to work for you.

It needs to take into account something about you and your specific needs. It would be best if you also had a different fuelling strategy depending on your body composition and performance goals. For example, the offseason might be a time to fuel differently, compared to your peak race season, where we want to train our gut and get used to our race fuel plan.


Recovery Nutrition

It’s essential to put the right building blocks back into your high-performance machine quickly after training. Aim to eat your recovery meal within 30-45 minutes after your session.

What your recovery meal is made up of should be specific to you. But it will depend on a few key factors:

  1. The duration and intensity of the session you’re recovering from – the harder the workout, the more diligent you will need to be with your recovery
  2. What your lean muscle mass is – the more you have, the more fuel you will need
  3. What your body composition goals are – if body fat loss is your goal, your recovery meal will look different compared to someone trying to gain weight.
  4. Where you are in your triathlon season – on-season fuelling can sometimes be higher than off-season nutrition, where your overall training volume is lower.
  5. When you’re training again next – if your recovery window is short, i.e., less than 24 hours, your recovery meal should be prioritized so you can back up and go again soon.

Focus on the 4 R’s of recovery

  1. Refuel with carbohydrates – how much you need is specific to you. 
  2. Repair with protein – somewhere between 20-40g as an initial target
  3. Rehydrate with water – how much depends on your sweat losses
  4. Revitalize with nutrients from natural foods 

A protein shake or pre-packaged recovery drink can be tempting, but this may only satisfy requirement #1 of our four Rs. Instead, I’d encourage you to build your perfect recovery meal based on real food rather than supplements, as there are many more nutrients we get from food.

Race Day Strategy

You’ve put in the hard work in training; now it’s time to piece it together into a race! What you eat and drink before and during a race can greatly impact your performance. 

The day before your race

Before toeing the start line, set yourself up for success with what you do the day before. Depending on the duration of the race you’re doing, your fuelling should reflect what you’re about to compete in. 

Carbohydrate loading becomes crucial for long-course racing such as Olympic Distance Triathlons, 70.3 or half Ironman triathlons, and full distance Ironmans, where a full fuel tank is a key to your success. 

The day before the race, focus on carbohydrate-rich foods low in fiber, such as bread and cereals, rice, noodles, pasta, low-fiber fruit and vegetables, milk, and yogurt. Be mindful of high fiber choices such as legumes (baked beans, lentils, chickpeas, red kidney beans) and typically ‘windy’ vegetables such as cabbage and onion.

You don’t need to stuff your face with plates of pasta like runners used to do in the 1980s; simply focus on carbohydrate-rich meals and go easy on the big-ass salads.

Triathlon Race Nutrition Plan

Your race nutrition plan will depend on three things:

  1. The distance of the event you’re competing in
  2. The pace that you’re able to hold in the race
  3. You! Your weight, caloric burn, and ability to tolerate different foods and fluids

There is no one-size-fits-all when it comes to your race nutrition. If you need help perfecting your race nutrition plan, join The Triathlon Nutrition Academy, where we help you fully customize your race nutrition plan for every triathlon distance. 

As a starting point, you can use the calorie calculator below to get a rough idea of how many calories you might need for your race. This is simply an educated guess based on equations that may or may not work for you. It’s a starting point, but it is not a personalized nutrition plan and should only be used as a guide.


Pre-Race Breakfast


What you eat in the morning before your race can have a massive impact on the success of your race. What you eat here should be something practiced and familiar. Use your pre-training nutrition as a starting point and seek help from a sports dietitian when you are ready to implement your perfect pre-race meal.

You can find many options for good pre-race and pre-training breakfasts in my recipe database.

Triathlon diet and nutrition for Triathlons Shorter Than 75minutes – Try-A-Tri, Sprint, Short Duathlons and Aquathlons

For short races, you should have enough fuel in your tank thanks to your nutrition the day before, so you’re unlikely to “hit the wall.” Suppose you’ve been tapering and including carbohydrates in your diet for a couple of days leading into the race. In that case, you will have enough carbohydrates stored in the form of glycogen to get you through the race.

Suppose you’re looking for a performance kick. In that case, there is good evidence that a mouth rinse of carbohydrates is enough to send sparks flying in the central nervous system and give you a pick-me-up when needed. Something to consider is if eating/drinking carbohydrates while racing is impractical or you find it difficult to digest. Try nibbling on a gel, storing a sports lolly in your cheek, or swishing a sports drink around your mouth.

Triathlon diet and nutrition for Triathlons Longer Than 90 minutes – long course, Olympic Distance, 70.3 Half Ironman, and full distance Ironmans or Ultraman Triathlons

Eating and drinking during a race will be imperative to reach the finish line in one piece. Everyone is different, so it’s worth investing time in developing a race nutrition plan with your sports dietitian.

Carbohydrate intake should be between 30-90g/hour, depending on the intensity and duration of the event. This is easily achieved with sports drinks, gels, sports lollies, bananas, and other food items such as sandwiches, homemade energy bars, fruit cake, etc.

To bump up your carbohydrate intake beyond 60 grams of carbs per hour, you’ll need to consider utilizing different types of carbohydrates (e.g., glucose + fructose) as these are absorbed differently. Training your gut to utilize different carbohydrate transport channels will increase your carbohydrate availability beyond what glucose alone can provide.

Fluid intake when racing

How much fluid you need to consume when racing is highly individual. It will come down to you and your sweat losses. The longer the event, the more fluids you will need to prevent dehydration. We know that dehydration beyond 2-3% of body weight negatively impacts performance, so work with a sports dietitian to understand your fluid requirements.

“The golden rule of racing – Never try anything new on race day! Make sure you practice!”

Supplements to consider

As a sports dietitian, I have a real food-first philosophy. A supplement is just that – it should supplement an already good foundational diet. Unless you have a nutrient deficiency, you should be able to get everything you need from what you eat daily without needing to take a supplement.

Supplements are the sprinkles on the icing on your nutritional cake. If you want your sprinkles to stick, you must first work on the cake base and icing layers.

Once you have your cake baked, here are some performance-enhancing supplements to consider.

Protein Powder

Protein powder, while a supplement, can be helpful as a convenient option when you can’t get to real food. 

If you use a protein powder, check the ingredients list and ensure you’re comfortable with what’s in it. Many protein powders are packed with random ingredients that are risky. It should contain a whey protein isolate or whey protein concentrate, perhaps a sweetener or a flavor, and that’s about it. 


Caffeine is well known to boost endurance performance. It is a supplement worth playing with once you first have the foundations of your triathlon diet. 

Caffeine comes in many forms – it doesn’t mean you need to start drinking coffee if you’re not a coffee lover. A lot of sports nutrition products like gels, sports drinks, blocks, and chews contain caffeine. 

It’s not my usual Dietitian Approved recommendation, but cola or coke is a great option for endurance racing as it contains caffeine, carbohydrate, fluid, and electrolytes. Not one for everyday use, but used strategically can be a significant boost.

Again, how much caffeine you need is individual (are you getting the vibe there’s not a one-size-fits-all with nutrition?!). It depends on your size, event duration, and tolerance. But more is not better when it comes to caffeine. It’s about finding the smallest possible dose to give you the maximum effect.

Other Common Supplements for Triathletes

You may have likely heard that the following supplements are helpful for endurance athletes.

  • Vitamin B
  • Omega 3
  • Multivitamins
  • Magnesium

However, I only recommend taking these supplements after seeking the guidance of your doctor or sports dietitian first. 


When it comes to your triathlon diet, there is no one-size-fits-all. How you fuel your body depends on your training program, body composition goals, type, genetics, gender, and lifestyle. A great place to start is focusing on natural foods first and matching your fuelling strategy to the demands of your training day.

If you want to optimize your triathlon diet, seek help from a triathlon sports dietitian to fast-track your success and reach your goals faster.

About The Author

Taryn Richardson is an Advanced Sports Dietitian from Dietitian Approved and ‘retired’ age group triathlete. She holds a Bachelor of Health Science Degree in Nutrition & Dietetics (Hons), an International Olympic Committee diploma in sports nutrition, and is an ISAK-accredited anthropometrist. She is the founder of the Triathlon Nutrition Academy program, which helps triathletes understand exactly what to eat for their triathlon diet, to enhance performance training and racing.