Triathlon Nutrition Guide: Before, During & After Race (What Not To Eat !!!)


Triathlons put an extraordinary amount of pressure and stress on the body; through the event itself and also the training that leads up to it. In order to withstand that pressure, we as triathletes need to pay close attention to what we are eating, and how much we are eating. But just what, and how much, should we be eating? The answer may surprise you.

Triathletes should be consuming around 3,000-4,000 calories per day during training. Around 60 percent of these calories should come from carbohydrates, 20 percent should come from fat and 20 percent should come from protein. These percentages may vary slightly depending on how much training is needed that week but it is agreed that a high carbohydrate diet is the way to go for endurance athletes (source).

What Should You Not Eat Before A Triathlon Race?

Avoid fatty foods because they will not contain the carbohydrates that you need to power your body in the middle and latter stages of the race. A fried breakfast may look very appealing but it is going to make you lethargic and heavy which is not what you want.

As important as what you should eat before a triathlon is what you should not eat before a triathlon. As a rule of thumb, stay away from anything that has not been a part of your diet in the weeks leading up to the event. You may read that quinoa is a good source of carbohydrates, but if you have never tried it before then why risk upsetting your stomach just before the event.

Also steer clear of high fiber foods, particularly on the morning of the race. High-fiber foods do not contain the carbohydrates that your body needs for the race. In addition, high fiber foods will increase the frequency of bowel movements, as well as make you feel bloated (source). This could lead to a very uncomfortable race ahead of you.

How Many Calories Do Triathletes Normaly Eat?

Put simply, not enough! Research by Frentsos and Baer took a look at the diets of 6 elite triathletes and showed that the average calories consumed per day was just 2,318. This was under the recommended 2,500 per day for an average adult male (source) and well under the recommendation for high-level endurance athletes.

Triathletes should be consuming around 3000-4000 calories per day, with 45-65% of these calories coming from carbohydrates depending on the training loads of that specific week (source).

To give you some idea of what that much food really looks like, take a look at the table below:

Breakfast (Blueberry Oatmeal)    1 cup dry oatmeal cooked with 1 cup of 1% milk and 1 cup water 1 cup blueberries 1 teaspoon cinnamon 1/4 cup slivered almonds
Snack  1 cup low-fat cottage cheese 1 sliced peach 10 whole-wheat crackers
Lunch (Roasted veggie and turkey pita)  1 large whole wheat pita 1 cup roasted red peppers 1 cup sautéed or roasted zucchini (in ½ tablespoon olive oil) 1/4 cup mozzarella cheese 2 ounces turkey breast 1 medium-sized baked sweet potato 2 small fig cookies
Snack  Apple with 1 tablespoon peanut butter
Training Session  Sports drink (16 ounces)
Dinner (Pasta with veggies and meat sauce)1 1/2 cups cooked whole-grain spaghetti 1 tbsp olive oil 1 cup zucchini 1 cup cherry tomatoes 1 cup marinara sauce 5 ounces 90/10 (ratio of meat to fat) ground beef
Snack  1 cup raspberries and 1 tablespoon dark chocolate chips
Typical Triathlete Daily Diet

Plan taken from: verywellfit.com

This plan provides 3,300 calories (28% fat, 53% carbohydrates, and 19% protein).

How Much Should You Eat During A Triathlon Race?

During the triathlon race itself you will burn an incredible number of calories. A person of average body mass 70 kg will burn approximately;

  • 1584 calories for a Sprint triathlon
  • 2230 calories for an Olympic triathlon
  • 9622 calories for an Ironman triathlon

Obviously, you are not going to be trying to replace all of these calories during the race but this should give you a clue that eating during the race is important, because your body simply cannot store enough energy for long-distance triathlons. If you are interested in knowing more about calories used during the event then check out our article ‘How Many Calories Are Consumed In Triathlons; Why Is It Important?’.

During events you want to be consuming 150-300 calories per hour (source), so for an average half Ironman time of 6:04:49 (source) you will be looking to take on board 900-1,800 calories during the race.

Remember that it will be a lot easier to digest food while on the bike, as opposed to the run where you will be bouncing up and down which will inhibit digestion and may cause nausea. As such, you want to be getting a majority of these calories in on the bike and eating small amounts at regular intervals.

What Should You Eat During A Triathlon Race?

Given that we need to get 150-300 calories per hour into our bodies, we need to be sensible in how we go about this. It is not like we can have a roast dinner waiting for us in the transition area. The most popular forms of nutrition during a triathlon race are energy bars, gels and energy drinks because they are easy to carry, take up little space and pack a great amount of energy into them. The table below gives the nutritional values for each:

Energy SourceNutritional Values
High5 Slow-Release Energy Bar (40g)151 calories
GU Energy Gel (32g)100 calories
SIS Go Energy Drink Powder (50g)189 calories
Energy Gel Calories

Most events will have drink stations where you can grab a banana, water and an energy drink at but having a few bars and gels is always a good idea as you can test them out in training first and see how your body responds to them.

Check out our recommended energy gel in our list of Best Triathlon Battle-Tested Budget Gear

You may find that your body digests one product better than another, or has a larger effect on your body. Also, if you find a favorite snack then your mind will begin to associate that snack with the hard training you have been doing and this can give a mental boost during the race.

What Should You Eat The Week Leading Up To A Triathlon Race?

The week leading up to a triathlon is an important time; you have tapered off your training and are focusing on getting good rest and being mentally prepared for the challenge ahead. But what should you eat in the week leading up to a triathlon? The short answer is that you should have a carbohydrate-rich diet. To answer this properly, however, we will need to look at some simple science around how the body uses the energy that is stored within it.

The body uses energy stores in the following order: Glycogen, Carbohydrates, Fat. The reason being is that glycogen is the simplest form of energy. It is stored in the muscles and liver and is ready for the body to instantly turn into energy.

Carbohydrates are more complex compounds that the body needs to first break down into simple carbohydrates before it can use them as energy. Fats are the most complex forms of energy, and so these are used once all the other sources have been exhausted.

Ideally, we would stock up on all the energy we need for the race in the form of glycogen, but there is a limit to how much glycogen the body can store. This is around 1,750 calories for a 70kg athlete (source). This is just enough to get you through a sprint triathlon, but not enough to get you through anything longer than that.

As such, the body will need to turn to carbohydrates to keep performing at an optimal level. This is why, in the week leading up to the triathlon you should be eating plenty of pasta, potatoes, and rice. Stay away from any new foods and also keep away from spicy foods once you get to 3 days out from the event.

Finally, drink lots of water to ensure that you are properly hydrated in the days leading up to the event, and save the alcoholic drinks until after the event.

What Should You Eat The Night Before A Triathlon Race?

There is a lot of discussion on what you should eat on the night before a triathlon. Is it ok to have a pizza? Can I drink a beer the night before an event? From a nutritional standpoint, the answer to both of those questions is a resounding no. You should not be stuffing down a high-fat dinner or drinking anything that will dehydrate you. However, this comes with a caveat.

There is another school of thought that says that if you have been sensible with your diet leading up to the event, then the benefit of being able to relax with friends and loved ones before the event over a pizza and a glass of wine outweighs the negatives.

You need to be as relaxed as possible so that you can get a good night’s sleep and be in the right frame of mind when you reach the start line in the morning. For some, this might mean sticking to the diet they have been on leading up to the event; pasta with aubergines and tomatoes for example. For others, this will mean a ‘treat’ meal that they enjoy and that they feel they have earned through the hard weeks of training.

Ultimately the hard work has been done already, so as long as you eat in moderation then you will not undo all that good work with one pizza. But still, keep away from anything spicy and keep alcohol consumption under 2 units.

What Should You Eat For Breakfast Before A Triathlon Race?

A good idea is to try to eat something that is going to boost your glycogen stores and will be easy to digest. Muesli with a banana is a fine choice, or peanut butter on toast. Feel free to have a cup of coffee too if this is part of your normal breakfast routine.

You want to be eating no later than 2.5 hours before the event starts. Given that triathlons are a long day, this could well mean breakfast comes at 4 or 5 am. With the excitement and nerves of the event possibly playing a factor it is a wise choice to stick to something that you are used to eating for breakfast so that you limit any issues with digestion.

What Should You Eat After A Triathlon Race?

When thinking about what to eat after a triathlon it is important to consider what the goal is. The main goal should be recovery so that you can get back to training, or at least walk around without pain, as soon as possible.

In order to speed up recovery, it is important to focus on what you are putting into your body in the 8 – 24 hours after the event (source). In particular, you should try to replace the protein stores which are the building blocks to repair your muscles. Rich sources of protein can be found in the following foods:

Food SourceServing SizeProtein
Lean Ground Beef (90%)3 oz22g
Salmon or Tuna3 oz23g
Turkey Breast (roasted)3oz26g
Dry Roasted Peanuts½ cup18g
Rich Triathlete Protein Sources

Data taken from www.uofmhealth.org

In addition to protein, it is important to get a good amount of carbohydrates into your body in order to enhance glycogen resynthesis. This is important to restore muscle function and performance after a long-distance triathlon and should be consumed as soon as possible after finishing your race. It is suggested that 40-60 g of carbohydrate should be consumed as soon as possible after the event and at 1-hr intervals for 5 hours after the race (source).

A great source of carbohydrates that is easy to pack into your kit bag is bananas. One large banana has around 31 grams of carbohydrates, so if you can eat a couple of bananas straight after the event then it will massively aid recovery.

It should be noted that a large intake of carbohydrates may not be necessary after a sprint race, as you will most likely be using stores glycogen rather than relying on breaking down large amounts of complex carbohydrates. Also, if you are not going to be heading back to training in the next 3 days or so, then the body will replenish the lost carbohydrates gradually so there is no need to go too heavy on the carbs in this case.

Antioxidants may reduce inflammation and muscle soreness, so it may be a good idea to include this into your recovery meal plan. Blueberries and dark chocolate are both a great source of antioxidants and have the added benefit of being a delicious combination.  

What Food Should You Avoid After A Triathlon Race?

After completing an epic challenge such as a triathlon you could be forgiven for wanting to have a blow-out meal of a burger and chips, washed down with an ice-cold beer, but the reality is that you should wait a couple of days before you treat yourself. Allow the body to fully recover first and you will enjoy your treat a lot more.

Avoid fatty foods such as burgers, pizzas and ice-cream because they will slow down the delivery of the nutrients your body needs.

Excessive alcohol can also slow down recovery and will add to dehydration, so if you do choose to have a celebratory drink then do so in moderation. You may also find that you are more susceptible to the effects of alcohol after an endurance event.

Finally, although it may look like a healthy option, salads are not really a great choice for a post-race meal. Your body needs protein and carbohydrates, neither of which are going to be provided with a simple salad. A good option here would be to throw in a chicken breast and some pine nuts, along with some boiled potatoes in order to give your body what it really needs.

What Should Kids Eat For Triathlons?

If your child is into triathlons then the chances are that you are having them eat healthily already. A balanced diet that is high in carbohydrates, moderate in protein, and low in fat will set your child up perfectly, not just for triathlons but for a healthy life in general.

  • On the night before the event keep with a balanced meal, something like pasta with some fresh veggies and tuna would be fine. Be aware that there is no need to make the meal any larger than normal. Kids are more sensitive to changes in diet and meal size so it is best to keep everything familiar.
  • In the days leading up to the event make sure that your child is properly hydrated. Have them carry a water bottle with them at school and sip on it throughout the day.
  • Around half an hour before the event have a light snack prepared which is high in carbohydrates. A banana or half a bagel will do the job just fine. If you go for anything that is high in protein or fat then it will take longer for the body to process and leave them feeling sluggish.
  • After a triathlon it is important to ensure your child hydrates properly. The chances are they will be on a high so you may need to remind them to drink plenty. Give them a treat that will aid recovery; chocolate milk is a good choice because it tastes delicious and is a good source of protein and carbohydrates.
  • Finally, 2-3 hours after the event have a healthy balanced meal prepared so that you can sit around the table as a family and celebrate your child’s awesome achievement.

Final Thoughts

As the saying goes; you are what you eat

You are an endurance athlete, and as such your diet takes on more importance than the average person. Not only do you need to make sure that you are getting enough food, but you need to be sure that you balance your carbs, protein, and fats in a way that will provide optimum performance for you so that you can train hard and recover fast.

Count up how many calories you eat over a normal day, and look at the make-up of those calories so that you can see where you need to adjust your diet. While it may seem like quite a lot of work, once you have your diet well organized your body will repay you so it is a worthwhile investment of your time.

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