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Maximizing Race Day Energy: A Complete Guide to Pre-Race Nutrition

April 26, 2024
Manfred Bortenschlager

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Are you gearing up for a big race, maybe a marathon, a half-marathon, or an obstacle course race, and wondering how to get your body primed for peak performance? Well, you're in the right place! 

Fueling up properly before an endurance competition like a marathon or a Spartan race is crucial for performing optimally and enjoying the event. If you put garbage in, you will get garbage out. 

In this article, we’ll cover how to fuel up before a race, what the ideal macro split is for endurance athletes, how to fuel up before and during the race, and how you can set this up for your clients in PT Distinction.

Ideal Nutrition for Endurance Races

In order to determine your ideal nutritional intake, we need to consider two important numbers:

  1. Your total daily energy expenditure (TDEE)
  2. Your macro split

Your TDEE is a measure of how many calories you burn per day. You can either estimate your TDEE using an online calculator, or measure it by using a sports watch, activity tracker, or a DEXA scan, which is the most accurate way.

Your TDEE is your benchmark of how many calories you need to consume per day. It’s ok to consume slightly over that because, in this scenario, your goal is not weight loss but race performance. 

The second number is your macro split. This is the split between the three macronutrients -- proteins, carbohydrates, and fats -- that make up your daily caloric consumption.

The ideal macro split for endurance athletes typically involves a higher proportion of carbohydrates, a moderate amount of protein, and a smaller amount of fat.

Macro Split for Endurance: Carbs, Proteins, and Fats


Carbohydrates are the primary fuel source for endurance activities like running.

Aim for about 55-65% of your total daily calorie intake to come from carbohydrates. Choose complex carbohydrates such as whole grains, fruits, vegetables, and legumes.


Protein is crucial for muscle repair and recovery, but endurance runners typically don't require as much protein as strength athletes.

Aim for around 15-20% of your total daily calorie intake to come from protein sources.

Lean sources include chicken, turkey, fish, tofu, beans, and lentils.


While fat is also an important energy source for endurance activities, it should make up a smaller portion of your total calorie intake compared to carbohydrates and protein.

Aim for about 20-25% of your total daily calorie intake to come from healthy fats such as avocados, nuts, seeds, olive oil, and fatty fish like salmon.

Risk of Consuming the Wrong Nutrition During Race Preparation

Consuming the wrong nutrition on the days before the race and on race day can seriously impact your performance and overall experience. In some cases, it can even be dangerous. 

Not enough intake of carbs before and during the race can lead to depleted glycogen stores and decreased energy levels.

This will result in fatigue, sluggishness, and an inability to maintain pace.

If you are dehydrated and don’t consume sufficient electrolytes just before and during the race can lead to muscle cramps or spasms.

You can even injure yourself. Dehydration can also lead to hyponatremia (low blood sodium levels) and result in dizziness, headache, or even vomiting. 

Consuming foods too high in fiber or too fatty or consuming large quantities of food too close to the race start can cause gastrointestinal issues such as bloating, nausea, vomiting, diarrhea, or abdominal pain. 

Inadequate fueling or hydration can result in a lack of energy and clarity, which may lead to mental fatigue, confusion, and disorientation, impairing decision-making, focus, and cognitive function during the race.

The risk of injury (accidents due to lack of concentration) is increased and most certainly you will simply not enjoy the race.

Eating and drinking right is a key ingredient to having a great race experience.

After all, you don’t want to invest all your time and energy in race prep but then end up dissatisfied or even frustrated due to poor food choices.

Nutrition Advice for the Days Just Before a Race

On the days leading up to the race you should stay very disciplined with sticking to your daily caloric intake goal and your macro split.

Regarding food choices, complex carbohydrates are essential. You will find them in whole grains like brown rice, quinoa, oats, and pasta.

These will provide sustained energy for the race. In addition, load up on fruits and veggies like bananas, berries, sweet potatoes, spinach, and broccoli.

They're rich in vitamins, minerals, and antioxidants to support your immune system and overall health.

For your protein part, include lean protein sources such as chicken, turkey, fish, tofu, beans, and legumes to aid in muscle repair and recovery.

Finally, incorporate sources of healthy fats like avocados, nuts, seeds, and olive oil for sustained energy and satiety.

Do not underestimate dehydration. Drink plenty of water throughout the day to ensure you're well-hydrated leading up to the race.

General recommendations about how much we should drink are misleading because it depends a lot on your genetic factors and lifestyle.

You can gauge it by thirst, but also the color of your urine. In case of doubt, drink too much rather than too little. 

Consider adding electrolyte drinks or sports drinks to your hydration plan to replenish electrolytes lost through sweat. Here’s a little trick I use instead of buying over-expensive electrolyte drinks:

Just use plain water, add pure lemon juice, sea salt, and a bit of honey. There’s your self-made electrolyte drink.

In terms of timing, start hydrating well several days before the race to ensure your body is adequately prepared. Increase your carbohydrate intake gradually in the days leading up to the race, with a focus on carb-loading the evening before the race.

Also, don’t overeat. Just eat slowly and reasonably till you feel just not hungry any more. This last meal (except a light breakfast on race day, see next section) should be around 12-16 hours before the race to allow enough time for digestion and to prevent any gastrointestinal discomfort on race day. And: no alcohol.

One last thing that you must not underestimate is sleep

Sleep is the king of all recovery mechanisms and significantly influences your body’s restorative and digestive functions.

While preparing for a race, you put a lot of strain on your body. During sleep your body recovers the best. Make sure you get the right amount and quality of sleep. Make this a priority, especially the days before the race.

If you cannot achieve this during the night, try to squeeze in a little nap during the day. 

Fueling up on Race Day

On race day, you'll want to stick to a similar macro split as you do during your training, with a slightly more emphasis on carbs for energy.

You will need to adjust your intake timing and quantities to accommodate the demands of the race. 

And most importantly: Don’t do anything new which you haven’t tried before (diarrhea from untested energy gels anyone?). 

Aim to consume a smallish, carbohydrate-rich breakfast or meal 3-4 hours before the race start time to top up your glycogen stores and provide sustained energy throughout the race.

Focus on easily digestible carbs like oatmeal topped with banana, blueberry or honey. Avoid high-fiber foods like bran cereals or raw vegetables on race day, as they can cause digestive issues.

Have a small snack half an hour before the race. Have some easily digestible, simple carbohydrates such as a small banana or half a muesli bar to provide a quick energy boost.

Continue sipping on water or a sports drink leading up to the race to ensure you're well-hydrated. Drink about a quarter of a liter of water just before the race. Go to the toilet before the race!

During the race make sure that you stop at most of the aid stations and drink to stay hydrated and maintain electrolyte balance.

It's essential to consume carbohydrates during the race to maintain energy levels. This can include consuming sports drinks, energy gels, or other easily digestible carbs at regular intervals, typically every 30-45 minutes.

I repeat my super important advice: Don’t try anything new during the race. Only rely on well-tested drinks, foods, and equipment. It can backfire badly.

How to Coach Clients With PT Distinction

So far we have covered principles and practical tips about fueling up before a race. Which is great to know but it can be challenging to actually monitor and execute correctly.

Thankfully, fitness and coaching platforms and apps like PT Distinction were built exactly for that purpose. It can be used for athletes and coaches alike to create exercise and nutrition plans and then monitor progress towards the desired goal.

In this section, we will cover how some features of the PT Distinction platform can be used to define targets like calorie intake and macro splits and then monitor compliance.

Define Calorie Goal and Macro Split

As introduced at the beginning of this article, your race nutrition starts with your daily caloric intake goal and your macro split. Both can be set and tracked very conveniently using PT Distinction. Below is a video that explains very well how to do this best.

Add a Nutrition Plan

If coaches and clients want to share specific nutrition plans including meal ideas, recipes, or even shopping lists, then this can be achieved in PT Distinction too.

The article How to Coach Nutrition on PT Distinction describes that quite nicely. 

As a coach you choose from a wide variety of pre-loaded nutrition plans from the library or you can create and add your own. The video below demonstrates how this is done. 

Monitor Compliance

PT Distinction offers two ways to monitor compliance or track food intake. The first one is to track via the food diary. Tracking options include photo, or text.

The frequency can be freely defined. 

The other way is to set up tracking via daily habits, which is a simple yes/no selection every day.

Coaches can in addition configure pre-scheduled messages to remind or re-inforce, or for any clarifications coaches and clients can communicate at any time via the chat function.

Gold Standard: Integration with MyFitnessPal

One of the industry-leading and most advanced food trackers is MyFitnessPal. PT Distinction offers to integrate seamlessly with MyFitnessPal.

Clients can use it to track their meals (including scanning barcodes to automatically obtain nutritional values) and all the data is synchronized with the PT Distinction dashboard.

So, everything is nice in one place. Here is a short video tutorial about how this is done.  

Meal Planning on Steroids: The AI Meal Plan Builder

A final feature that can really enhance a coach's work is the AI meal plan builder. You can leverage artificial intelligence to develop a whole meal plan for several weeks within a couple of minutes.

You only need to specify a couple of parameters (like macro split or any specific dietary preferences) and then AI simply does its magic. 

The first screenshot below shows the interface that’s really easy to use.

This is the resulting meal plan that AI created, which can then be shared with the client.

The video below shows a more detailed demo about how to use PT Distinction’s AI meal plan builder.

The Ideal Fuel Before a Race

Our bodies are magical. They work like amazing engines and are capable of insane performances. However, we also need to take care of them.

Nutrition for our bodies is like the gasoline for combustion engines. It needs to be adequate and of high quality. Garbage in will lead to garbage out. 

In today’s article we covered how to ideally fuel up before a race to deliver the performance we aim for and have a great time.

We focused on the macro split specifically for endurance competitions and presented practical tips about when to eat what on the days before the race.

Finally, we showed how PT Distinction can be used to specify meal plans and track nutritional habits.

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