Blog Post

Supplements for Endurance Athletes

Supplements for Endurance Athletes Featured Image

There are many ways that supplements can be beneficial for endurance athletes. As a sports dietitian I typically take a “food first”, but not necessarily a “food only” approach. In many cases, it is possible to optimise things through food. But there are also times when supplements can be beneficial. The best example is when achieving certain optimal intakes through food is unrealistic.

This post will be focused on supplements, but I also have an article on overall endurance nutrition.

For this post, the structure will be:

  1. There is a clear focus on supplements that can help. I won’t spend time mentioning supplements that have been proposed to help but not held up to scrutiny when researched.
  2. It will be a comprehensive list, but just because a supplement is not mentioned does not mean it is not beneficial. There is a long list of options with potential benefits, and it would be impossible to put it all into a single post.
  3. I will split things up into two sections. The first section will be a broad range of supplements that are typically likely to have benefits. The second section will be an “honourable mention” section for supplements that have more narrow situations where they might be beneficial.

Broad Supplements Worth Considering

While not all these supplements will be specifically relevant to you, these are some of the options that many people will benefit from.

Sports Gels

Sports Gels

Sports gels are a convenient way to get easily digestible carbs in while training or competing. They can also contain other components such as caffeine or electrolytes.

Often, but not always, they will also contain multiple sources of carbohydrates (for example, glucose and fructose). This has been shown to allow the body to tolerate taking on even more carbs while exercising at a high intensity.

Sometimes people will criticise gels and say that whole foods are better. While there are many situations whole foods can be suitable, the main counterargument to this is:

  1. Gels are typically easier to digest.
  2. The ratio of ingredients in gels is often optimised to allow higher levels of intake without GI issues.

If you are trying to maximise how many carbs you are taking on per hour, it can often be harder to achieve that through food instead of gels.

Dosage and how to take: The best endurance athletes in the world often consume 90g+ of carbs per hour. Most people will not be able to tolerate that, but it is also a trainable ability. The simplest approach is to pick a carb target per hour and aim for that either through gels alone or using a combo of options.

Example: 50g of carbs per hour could be made up of 2x gels containing 25g of carbs each.

Sports Drinks

Unbranded Sports Drinks

Sports drinks have similar qualities to sports gels, although they also contribute more to fluid intake. They often have a larger emphasis on electrolytes too.

Dosage and how to take: In many cases, it makes sense to have a carb target you are aiming for per hour AND to just drink enough fluid. Sports drinks can contribute to both of those things.

Example: Somebody aiming for 60g of carbs per hour could consume ~35g coming from 600ml of Powerade and then ~25g from a gel. Then if they still want more total fluid, they could drink water on top of this.

Caffeine

Revvies Energy Strips

Beyond just hyping you up and making you feel more motivated, caffeine can directly improve your performance.

At minimum, even at relatively low dosages caffeine can reduce the rate of perceived effort (RPE).

Caffeine can directly improve performance at higher dosages though.

There are many proposed mechanisms for how it contributes to this. It is likely a combination of multiple variables, including the ones listed below:

  • Central nervous system stimulation
  • Adrenaline release
  • Enhanced fat oxidation
  • Improved muscle contractility
  • Glycogen sparing
  • Increased dopamine levels
  • Neuromuscular function.

Dosage and how to take: The gold standard would be to take 3-6mg/kg prior to a race, and then top up with small amounts throughout the race. There is individual variation though.

Lower amounts are likely more relevant for reducing RPE. Higher amounts are likely more relevant for directly improving performance. Since caffeine dosing is such a complex and individual topic, it could be worth reading our article specifically on the topic.

Beetroot Juice

Beet-It Supplement

Beetroot juice has consistently been shown to improve endurance performance.

The main mechanism is that it contains nitric oxide, which increases vasodilation. This leads to improved blood flow and oxygen transportation.

There are other mechanisms related to the antioxidants too.

Dosage and how to take: 5-7mmol of nitrate 2-3 hours before a race. This translates to either 500ml of beetroot juice or a 70ml concentrated shot.

The benefits peak after 90 minutes and last for 6-8 hours.

There also appear to be further benefits to taking it daily for up to 6 days leading up to a race. Taking it longer than that is fine, the benefits just do not seem to increase further.


Probiotics

Lifespace Probiotic

Probiotics often are not the first thing that comes to mind as a supplement for endurance athletes. There is solid research showing that they can help though.

At a minimum, probiotics have been shown to consistently reduce the likelihood of upper-respiratory tract infections in endurance athletes.

This would translate to fewer training sessions and races being impacted (or missed) due to illness.

The mechanism is:

  1. They can play a role in the immune system and stimulate the production and activation of antibodies.
  2. They can strengthen the barrier of the mucosal lining, making it difficult for pathogens to get through.
  3. They inhibit the growth of harmful bacteria.
  4. They could reduce inflammation – and that inflammation plays a role in the symptoms of upper respiratory tract infections.

There have been some studies linking probiotics with the following, but research is weaker in these spaces:

  • Reduced frequency of gut symptoms while exercising.
  • Reductions in inflammation and oxidative stress.
  • Slight improvements in endurance performance, measured by time trials and time to exhaustion.

Dosage and how to take: It’s complex, so I’ll point you to this article which has a thorough breakdown in the “dosage” section.

Sodium and Electrolytes

Salt Stix Electrolyte Caps

This one almost fell into the “honourable mentions” category, so there needs to be some added context.

Sodium and electrolytes have far less evidence indicating that they improve endurance performance than most would expect.

For example, a systematic review looking at 5 studies on sodium found no improvements in 4 studies and one huge improvement (7.8%) in another.

Even when looking at research on cramps, things are less promising than most people would expect.

While electrolytes CAN play a role in cramps, based on the available research, it seems like on average it is not the driving force in most athletes at higher levels who are cramping.

That said, there are a few things I would want to note:

  1. It makes sense to have a good baseline intake of electrolytes. There is no downside. Although it is not typically the main reason athletes at higher levels are cramping, it is worth noting that most athletes at higher levels in endurance sports are consuming electrolytes during events.
  2. Sodium helps reduce urinary output. A lot of athletes struggle with longer endurance events and needing to use the bathroom.

Even without the research looking overly promising (except for that 7.8% improvement study), it makes sense to me that consuming sodium and electrolytes is likely still worth doing for longer events.

Dosage and how to take: Due to the lack of positive research, it’s hard to prescribe the “optimal” amount. For sodium specifically, a good ballpark recommendation is 500mg per hour.

A simple way to achieve this is through products like SaltStick Caps. These also contain the other electrolytes too.

Tart Cherry Juice/Extract

Tart Cherry Juice

Tart cherry products have been shown to help reduce muscle soreness and improve sleep.

The soreness aspect is particularly relevant for if you are looking for a way to improve recovery from big events.

Optimising sleep is beneficial for all athletes. Better sleep = better recovery.

It is not the most cost-effective supplement. But if it fits your budget comfortably, then it could be worth considering.

The mechanisms are largely related to the following:

  • Cherries are high in antioxidants.
  • Tart cherries are 5x higher in antioxidants than regular cherries.
  • When you juice a fruit, it makes it easier to consume more of it.
  • When you concentrate that juice, it makes it even easier.
  • Suddenly a 70ml shot of tart cherry juice is the antioxidant equivalent of consuming >20 serves of fruits/vegetables.
  • This largely explains the reduced muscle soreness. There is also an increase in natural melatonin production which helps explain the improved sleep.

Dosage and how to take: Either consume 70ml of concentrated tart cherry juice or consume tart cherry extract capsules instead.

Personally I would just use this after big events. Cost is a factor. But beyond that, while, antioxidants are typically viewed as a good thing, but there is potential for excessive consumption to have downsides. That discussion is beyond the scope of this article though, so if you want to dig deeper into that, I recommend reading this article.

Honourable Mentions

For this section, the descriptions will be briefer, with a focus on listing a wide range of options that could be worth considering.

Protein Powder

VPA Whey Protein Concentrate

Protein powder should be thought of as a convenient way of getting high-quality protein in. If you struggle to get enough in through food, protein powder can help.

Few endurance athletes will struggle to get enough in through food. Many endurance athletes require relatively high-calorie intakes to fuel their training, making it easier to get sufficient protein through food. But there will be exceptions where it could be relevant.

Beta-Alanine

Beta-Alanine

This supplement will not be relevant for many endurance athletes, but it is worth bringing it up as part of the discussion.

Beta-alanine is typically beneficial for improving performance in intense activities that are 1-10 minutes long.

The benefits come from its pH buffering effect, which is only relevant for activities at an intensity well beyond what can be sustained for 10+ minutes.

If somebody had a loose definition of an event requiring endurance that was also <10 minutes, this could be relevant.

Creatine

Creatine VPA

While the door has mostly been closed on creatine as beneficial for endurance sports there are some potential ways it can help.

Research indicates that it has potential benefits for short bursts, hills or end-of-race sprint finishes.

Indirectly, it could also benefit any resistance training or rehab work you do, which could carry over to improved performance too.

It is likely not directly improving race times noticeably, but it is worth having awareness of.

Collagen

Hydrolysed Collagen Peptides.

Collagen has potential for helping with injury recovery from tendon and ligament-related injuries.

The research is not rock-solid or anything. But the protocol of taking ~15g of collagen, 40-60 minutes before training/rehabbing the relevant area has shown promise in multiple studies.

If it helps with injury recovery, there is a chance it helps with injury prevention too.

NZ Blackcurrant Extract

NZ Blackcurrant Extract

NZ blackcurrants are exceptionally high in anthocyanins.

There is solid research showing that using this extract can help reduce muscle soreness and improve vasodilation.

The reason I have put this in the “honourable mentions” section is simply because the benefits overlap with beetroot and tart cherry juice.

The average improvement seen in research is 0.45%. This is quite a small improvement and only relevant for specific people.

Glycerol

Glycerol powder

Glycerol can help with “hyperhydration.” It helps the kidneys reabsorb more water. Studies have shown that 1L of extra water storage in the body is achievable with glycerol.

This could help delay performance decreases due to dehydration.

Omega 3

Omega 3 Supplements

Omega 3s can potentially help with reduced inflammation levels and a reduction in soreness. They also can help improve cardiovascular function in general.

Omega 3 could be consumed either through food or supplements. The supplement form would likely be more beneficial for somebody who otherwise would have a low intake through food.

Vitamin D

Vitamin D3

Vitamin D has a range of benefits including:

  • Improved bone mineral density
  • Better balance
  • Reduction in frequency/severity of illness
  • Potentially improved muscle function
  • Improved mood

Going from deficient to a good level of vitamin D comes with many benefits.

That said, it is typically only worth addressing if your levels are sub-optimal.

Since we get vitamin D from the sun, many endurance athletes easily exceed their needs without even trying.

Multivitamin

Multivitamin + Immune Function Blackmores

A multivitamin could be used as a “cover-all” option if you have a lot of gaps in your diet.

Typically, this should not be needed. Due to overall calorie intake being quite high, many athletes focused on nutrition also have a great intake of micronutrients.

If you did have a lot of gaps in your diet that you can identify though, it could be worth adding this.

Summary

While a food-first approach makes sense, there is a long list of supplements that can have benefits under certain circumstances.

Prioritising supplements over a nutritious diet would be silly. But statistically, almost all elite athletes use supplements. It makes sense to have awareness of which ones could be beneficial for you and to take advantage of the ones that can help improve your performance.

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.