Best Supplements For Endurance Athletes

Table of Contents

As someone who likes to run for miles, I understand the importance of supplements and proper nutrition to enhance performance.

There’s only so much you can achieve with a perfect diet and training program. If you think you’ve reached the limits of your routine but need more, then running supplements may be able to help you.

Sit back, and let’s get started – there’s a lot to cover!

First Up, Have You Nailed The Basics?

If you think that supplements are going to help you improve your endurance, answer the following questions first:

  • Are you eating properly?
  • Are you exercising properly?

People seem to struggle with their diets commonly. They don’t hydrate nearly as much as they should, and their diets incorporate plenty of junk foods that are sub-optimal for athletic performance.

Before moving onto any supplements, you should first nail the basics. More precisely, you should become conscious of what you are eating and exercise effectively.

Now, no matter how you are eating and training, supplements probably will have some positive effect. However, without an established base, supplements are an unreasonable expense.

Most likely, if you were to fix your diet and start training effectively, you would get no worse and perhaps even better enhancements than with supplements.

To me, taking supplements without proper diet and exercise is the same as taking painkillers when you have a badly hurting tooth. The painkillers are sure going to make you feel better, but you aren’t actually treating the cause of the problem.

So before wasting any money on supplements, you should first try to polish the basics. After that, if you feel that you need better athletic performance, you may start considering supplements.

What Are The 10 Best Supplements For Endurance Athletes?


If you are sure that you need supplements to become better at your athletic discipline, then you will find a few suggestions in this section.

When writing this piece, I have used the following sources:

I suggest that you read these sources as well since I won’t be covering everything from there word for word. There’s a LOT of useful information there, and I’ve only kept the key points.

With that out of the way, let’s get started with the list of supplements for endurance athletes!

1. Carbohydrates

Depending on where you are getting carbohydrates from, they may or may not be considered a supplement. Regardless, I think that carbohydrates are important enough to be included in the list.

Consuming adequate amounts of carbohydrates is crucial to the performance of endurance athletes. Daily intake recommendations vary from source to source. 

The American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics (AND), and Dietitians of Canada (DC) recommend:

  • Moderate endurance exercise (1 hour per day): 5-7 grams per kilogram of body weight per day.
  • Moderate to high-intensity endurance exercise (1-3 hours per day): 6-10 grams per kilogram per day.
  • Moderate to high-intensity endurance exercise (4-5 hours per day). 10-12 grams per kilogram per day.

An adequate amount of carbohydrates is one of the basics I’ve talked about earlier. If you don’t consume enough carbohydrates daily, you can forget about improving your endurance.

When it comes to sources of carbohydrates, natural foods containing complex carbohydrates appear to be optimal. These are preferable because they don’t spike blood glucose levels and don’t build body fat as simple carbs do.

Simple carbs also seem not to have any advantages over complex carbohydrates in terms of exercise performance, so you could just avoid them.

Among the best sources of complex carbohydrates are whole grains, beans, peas, and vegetables. Try to build your diet around these to maximize your energy intake.

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2. BCAAs

Amino acids leucine, isoleucine, and valine comprise what is known as BCAAs. BCAAs are contained in animal foods such as meat, fish, and milk, and they are also available as a training supplement.

All three amino acids may be used as an energy source for muscles, while leucine may also be used to build muscle.

It appears that BCAA supplements have little direct effect on endurance athletes. Instead, where BCAAs tend to shine is strength training and bodybuilding, thanks to their muscle-building effects.

Still, though BCAAs may not improve your endurance, they will help you train harder and recover muscle damage faster after training.

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3. Beetroot or beet juice

Many studies have found positive effects of beetroot or beet juice on endurance in running, swimming, cycling, and rowing. As for strength training and bodybuilding, the effects of beetroot and beet juice haven’t been studied extensively.

In studies where the positive effects of beet juice were observed, the participants drank 2 cups of beet juice 2.5-3 hours before exercise. However, note that beet juice seems to be more likely to improve recreational performance than highly-trained endurance athletes.

The benefits of beetroot and beet juice for endurance possibly comes from nitrates. Beets and beet juice are among the best sources of nitrates in nature.

It’s thought that beets and beet juice improve endurance by converting some nitrates to nitric oxide and expanding blood vessels. The expansion of vessels improves blood flow and increases the delivery of oxygen and nutrients to the muscle, improving endurance. It also might speed up the removal of muscle waste products.

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4. Beta-alanine

Some studies have shown that beta-alanine provides small improvements in activities with intermittent efforts, like hockey or soccer. It’s yet unclear whether beta-alanine improves endurance in running or cycling, however.

In most studies, participants took 1.6-6.4 grams of beta-alanine daily for 4-8 weeks. In contrast, people typically get about 1 gram of beta-alanine per day from food. You should probably start in the lower range and see how this supplement works for you.

Beta-alanine is an amino acid found in meat, fish, and poultry. The supplement works by increasing muscle carnosine levels, which reduces the amount of lactic acid in the muscles, reducing fatigue and increasing muscular force.

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5. Caffeine

Caffeine is a stimulant contained in coffee, tea, and energy drinks. 

Research has shown that moderate amounts of caffeine increase energy levels and reduce fatigue for several hours. Caffeine especially helps in sports that require intermittent effort.

The effects of caffeine differ from athlete to athlete, so you may either see incredible results or no effect at all.

Caffeine doses for performance enhancement range from 2 to 6 milligrams per kilogram of bodyweight. Taking more than 6 milligrams doesn’t appear to bring noticeable endurance performance improvements, but it does increase side effects such as poor sleep, irritability, or anxiety.

If you want to give caffeine a shot, you should start with less (2 mg per kg) and see where it goes. If you get no results, you may try to increase the dose while keeping an eye on side effects.

6. L-glutamine

Low levels of L-glutamine (also known as glutamine) in the body can cause inflammation, muscle breakdown, and weaken the immune system. Although the body can synthesize glutamine, its levels may be insufficient in endurance athletes, prompting them to take glutamine as a supplement.

Glutamine’s effect mainly relies on its ability to accelerate muscle recovery. With that in mind, ensuring sufficient levels of glutamine in the body lets you exercise harder.

Another interesting effect of glutamine is increased sodium uptake. A study published in the Journal of the International Society of Sports Nutrition found that higher concentrations of L-glutamine improved sodium absorption, reducing muscle fatigue and maintaining muscle strength.

With that, glutamine may be beneficial for endurance athletes in accelerating muscle recovery and elevating energy levels.

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7. Omega-3 fatty acids

Omega-3 fatty acids can lower muscle inflammation and speed up recovery. 

These fats are abundant in seafood, plant oils, nuts & seeds, and fortified foods. However, according to Swolverine, the best source of Omega-3 fatty acids is krill oil. Krill oil is widely available, can reduce inflammation, relieve joint pain, improve joint mobility, and speed up recovery.

Omega-3 fats and krill oil are again among those supplements that improve endurance indirectly by allowing you to train more and recover faster.

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8. Sodium bicarbonate

Sodium bicarbonate (known to you as baking soda) has been shown to improve performance in intermittent loads or short, intense activities (like sprinting in football or soccer). 

However, the effects of sodium bicarbonate vary vastly from athlete to athlete. In some people, it may actually reduce performance.

The typical dose of sodium bicarbonate is 300 milligrams per kilogram of bodyweight. However, be mindful of side effects. Baking soda often causes vomiting, nausea, and water retention, and some people find sodium bicarbonate dissolved in water too salty.

It’s thought that sodium bicarbonate works by reducing the buildup of acids (including lactic acid) in muscles, reducing fatigue.

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9. Turmeric

Turmeric is similar to omega-3 fatty acids in its effects. Studies have shown that turmeric improves joint health, mobility, reduces muscle inflammation and soreness, and enhances muscle recovery.

When it comes particularly to anti-inflammation, turmeric is similar to Ibuprofen. A study published in the Journal of Medicinal Food compared the safety and effects of Ibuprofen and turmeric.

One group of participants with knee osteoarthritis took 1,200 milligrams of Ibuprofen per day, while the other took 1,500 milligrams of turmeric extract per day for 4 weeks.

At the end of the 4-week period, it was discovered that turmeric’s effects were comparable to those of Ibuprofen. However, turmeric showed weaker side effects on gastrointestinal health. 

With that, turmeric could be considered a safer alternative to ibuprofen. Thanks to its anti-inflammatory and recovery effects, it could also improve athletic performance in endurance athletes.

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10. Whey protein

Endurance athletes sometimes neglect protein because its primary role is muscle-building and recovery rather than energy provision. But protein is crucial precisely because it participates in muscle recovery!

The ACSM, DC, and AND recommend that endurance athletes consume 1.2-2 grams of protein per kilogram of body weight per day. Endurance athletes are generally recommended to consume protein in the lower range (1.2 g/kg/day).

Most people ingest sufficient amounts of protein with meat and other foods. For some endurance athletes, though, regular food’s protein supply may be inadequate, which forces them to resort to supplements.

An excellent protein supplement to try is whey protein. Whey protein is available in concentrate, isolate, and hydrolysate. Whey protein concentrate is less refined and contains more fat and carbs, while isolate and hydrolysate contain “purer” protein.

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11. Creatine

Creatine is a popular supplement among athletes, and recent research suggests that it can benefit endurance athletes who include sprints, high intensity intervals, or strength work in their training.

Creatine works by increasing the production of ATP, the main energy source for muscle contractions. This increase in energy can help endurance athletes push through the last few reps of a strength workout or maintain their speed during high-intensity intervals. Additionally, creatine has been shown to help increase muscle mass and strength, which can lead to improved running economy and faster race times.

However, it is important to note that creatine may not be effective for all athletes and should be taken as directed. As with any supplement, it is always best to consult with a healthcare professional before adding creatine to your training regimen.

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12. Iron

Iron is an essential mineral for endurance athletes as it plays a crucial role in the production of hemoglobin, a protein found in red blood cells that carries oxygen throughout the body.

During endurance exercise, the body requires more oxygen to produce energy, and adequate levels of iron ensure that the body can meet this demand. Iron also helps to prevent fatigue and improve recovery time by supporting the immune system and promoting the growth and repair of muscle tissue.

Endurance athletes, especially female athletes, are at a higher risk of iron deficiency due to increased iron loss through sweat, urine, and menstruation. Therefore, it is important for endurance athletes to maintain adequate iron levels through a balanced diet or supplements to optimize their performance and overall health.

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3 Tips For Safe And Effective Supplement Consumption

To close off this post, I’d like to give you 3 tips to help you more effectively and safely choose and consume endurance supplements.

1. Understand the difference between direct- and indirect-effect supplements

I’ve had a look at a bunch of supplements. If you’ve noticed, some supplements directly affect endurance, while others affect it indirectly.

Direct-effect supplements (like caffeine or beet juice) generally work by facilitating energy production and/or accelerating waste removal. In contrast, indirect-effect supplements (like BCAAs or glutamine) may improve performance by letting you train harder and have better gains.

This is important to understand because indirect-effect supplements may not help you if you don’t have nutritional deficiencies. Their effects will be the strongest if your current diet lacks crucial nutrients.

2. Mind side effects

Next, keep in mind that supplements may have side effects. Read the label of your supplement carefully and consume only as much as recommended. With supplements, more doesn’t always mean better – by consuming too much, you are risking your health without much gain.

3. Make sure you aren’t consuming prohibited substances

Finally, make sure that you aren’t consuming prohibited substances. To get started, check the WADA prohibited substance list – if you are competing professionally, you will find all the necessary information. But keep in mind that prohibited substances may vary from sport to sport.

Final Words On Supplements For Endurance

In the end, remember first to master the basics – your diet and training routine. If you nail these first, you will be able to use supplements much more efficiently.

Besides, adjusting your diet or training routine may cost you nothing at all, while supplements require additional investment.

I also suggest that you read other guides on the internet – there’s much more to this topic than I’ve covered! I’ve just kept this guide simple to make sure it’s short and easy to understand.

Kyla Clark
Kyla Clark
Kyla Clark writes about healthy living and fitness. She holds a Master's Degree in Physical Activity for Health which she obtained at the University of Edinburgh. Kyla has been working as a freelance writer for three years.