Blog Post

Nutrition for Endurance Athletes Q&A with Alicia Edge

Dan and Alicia Edge

What are common mistakes endurance athletes make with their nutrition, prior to seeing a sports dietitian?

I wish it wasn’t the case, but athletes often only think to invest in a Sports Dietitian once something has gone wrong in a race, however, I think that is pretty common in a lot of different aspects of sports. The best thing is that they are learning with their mistakes. Having an athlete have the perfect race after they come to see us has to be one of the highlights of our job for sure!

I think out of all the mistakes I see, there are some commonalities –

• Not practising or planning race nutrition before the big day;
• Listening to the well-meaning advice from training buddies or expo staff the day before a race and changing their plan;
• Misunderstanding carbohydrate loading and ending up on that start line feeling flat and bloated.
• Either over- or under-eating carbohydrate intake per hour.
• Misjudging hydration needs – this includes seeing athletes that have both over hydrated and under-hydrated.

Are there general guidelines you use for carb-loading?

It really depends on the individual, as there are a number of factors that influence how someone is best to prepare for their race. The amount and type of carbohydrate needed in the lead up to a race will be influenced by body weight, the individual’s build/muscle mass, training level and also their typical daily carbohydrate intake.

This individual approach ensures much better gut tolerance, while still optimising muscle glycogen (carbohydrate) stores.

Are there general guidelines you use for in-race nutrition?

When working with an athlete I always work from what they have tried previously so that recommendations are based on their preferences. From there, options are tailored with a focus on optimising carbohydrate intake and hydration.

The guidelines used for endurance events are more around race preparation. I always call my event nutrition plans a draft, as they are a continual work in progress that evolves and adapts with the athlete. In the lead up to the race it is important to train the gut to cope with the amount of fluid and carbohydrate that is optimal for the race per hour (can be anywhere from 40-90g of carbohydrate per hour), consider individual hydration needs, logistical challenges and basically train how they plan to race.

The research appears to be clear that low carb diets aren’t superior for endurance, but do you think might have some benefits for extreme ultra-endurance events?

At specific points in the lead up to endurance and ultra-endurance events, optimising fat utilisation is going to be a strategy that I work into an athlete’s nutrition strategy. Possibly surprising to some athletes, this doesn’t have to mean going keto or extreme dieting. Considering nutrition periodisation principles such as training low or sleeping low can all enhance training adaptations and improve fat utilisation.

In terms of ultra-endurance, the physiological demands and energy systems are different. As a result, those high-intensity efforts and high heart rates are simply not critical during the race for overall performance. This means that optimising fat as a primary fuel source can be a really useful strategy in improving what is called metabolic flexibility. However, this can be achieved through nutrition periodisation strategies without the need to be as restrictive as keto (by definition only 5-10% carbohydrate intake).

Often ultra-endurance events come with some pretty spectacular logistical considerations. Only this week I planned all nutrition for a seven-day ultra event where the athlete needed to carry ALL of their food and equipment – so of course, creating energy efficiencies and improved fat utilisation can prove extremely useful in reducing pack weight too!

Are there steps you would take to transition an athlete from keto to a higher carb diet if they had been on a keto diet for a while?

Being in ketosis and following this diet long-term impacts the gut microbiome and also the number of glucose transporters in the gut you have to absorb carbohydrate. As a result, transitioning out of ketosis needs to be done gradually in close consultation with the athlete to ensure tolerance. I often find that their daily habitual carbohydrate intake may remain lower than the average, but will still be more conducive to supporting the higher intensity training and racing demands.

Do you think athletes should be consuming some form of protein or amino acids (alongside carbohydrates) during training? Does this affect their performance during that session/event? Does it help minimise muscle-loss, which may affect their performance over the longer-term?

The use of BCAA (Branch-Chain Amino Acids) supplements by athletes and everyday active individuals has got a little out of hand. There are some instances where they can be useful, but this is a minority rather than a majority.

The inclusion of BCAA when completing resistance exercise in a fasted state can assist in maintaining lean mass and supporting muscle protein synthesis, particularly when in an energy deficit. However, if you have a good spread of protein over the day, chances are you will not have much need at all for BCAA supplementation in this space.

In the endurance setting, the inclusion of protein along with carbohydrate can also inhibit muscle protein breakdown, stimulate muscle protein synthesis and possibly improve the adaptations in the training scene. However, it’s inclusion has not been shown to improve performance when comparing carbohydrate + protein and carbohydrate alone.

Another possible reason to consider the inclusion of BCAAs/protein in endurance is for its possible role in preventing central fatigue (the loss of central drive and motivation). BCAAs compete with tryptophan at the blood-brain barrier and as a result, may reduce the abundance of serotonin caused by endurance exercise. The evidence is not definitive in this area however, so it remains a risk vs benefit discussion with each individual athlete.

If you could create a sports drink, what would you do differently from Gatorade/Powerade?

When recommending a Sports Drink, I always utilise a range of brands and concentrations based on the individual needs of the athlete. So I don’t think it is about changing the one formulation, but rather finding the option that is right for the individual – based on their hydration needs, sweat electrolyte losses, racing history, acclimatisation and most importantly, their tolerance and taste preference. There is no point designing (or recommending) the perfect drink if they are unable to tolerate it.

One thing that I think we will see more of in the future is the inclusion of glycerol in some Sports Drink brands as a hyperhydration solution.

What supplements and dosages would you recommend for endurance athletes and why?

The supplements recommended are really dependent on where the athlete is at with there daily food, training level, race length/conditions and performance goals. The initial input with an athlete is always on first optimising the base of their daily nutrition and from there optimising intake to suit there training and racing.

For most endurance athletes, sports foods are something that is essential. These include things like Sports Drinks, Gels, Electrolyte, Chews, Protein Powders and Liquid Meal Replacements. These can be useful for convenience, but also needed to help meet high energy needs in endurance training or racing, and can be an option that is much easier to absorb – particularly when fuelling at intensity. Where possible, I also encourage the use of real food fuelling options, known as ‘portables’.

When the areas of daily nutrition, nutrition timing and sports foods are dialled in, then it is time to consider the possible use of ergogenic aids. In the endurance scene, the most common (and well-evidenced) ones to consider are caffeine and nitrates. As mentioned above, the inclusion of BCAAs might be considered at times and there are some others to consider based on the risk vs. benefit calculation depending on the athlete.

In terms of medical supplementation, I think many take different vitamins and minerals as a ‘just in case’ policy. Instead, consider your intake and complete blood tests if you are concerned. In endurance athletes, the most common deficiencies I see in practice is by far iron and vitamin D, both of which are easy to test for with a blood test.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been interested in all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.