Best Supplements for Runners: Benefits, Doses and Risks

Which supplements help runners? Compare the evidence, doses and risks for caffeine, beetroot juice, creatine, iron, vitamin D, protein and electrolytes.

Walk into any sports nutrition shop and it can feel as though running now requires an entire cupboard of powders, capsules and brightly coloured drinks.

One product promises more energy. Another claims to prevent cramps. A third says it will improve recovery, protect your joints and help you run faster – all before breakfast.

The reality is far less dramatic. Most runners do not need a complicated supplement routine, and no powder can compensate for insufficient food, poor sleep or a training plan that leaves no room for recovery. However, a small number of supplements for runners can be useful when they solve a specific problem, are taken in an evidence-based way and have been tested in training first.

The important question is not simply, “Does this supplement work?” It is: “Could it help this runner, with this goal, in this situation?”

Here are eight options that may offer genuine value – and the limitations worth knowing before you spend your money.

This article provides general information, not individual medical advice. Speak to a GP, pharmacist or registered sports dietitian before taking a supplement if you have a medical condition, use medication, are pregnant or breastfeeding, or suspect a nutrient deficiency.

THE 8 BEST-VALUE SUPPLEMENTS FOR RUNNERS

Supplement	Potential value	Most useful for	Evidence verdict
Carbohydrate gels and drinks	Maintain blood glucose and provide fuel during longer runs	Long runs, half marathons, marathons and ultras	Strong
Caffeine	Reduce perceived effort and improve endurance performance	Races and selected hard sessions	Strong
Dietary nitrate or beetroot juice	Improve exercise efficiency and endurance capacity in some runners	Time trials and endurance races	Good, but individual response varies
Protein powder	Conveniently helps runners meet daily protein needs	Recovery, strength training and busy schedules	Useful for convenience
Creatine monohydrate	Support strength, power and repeated high-intensity efforts	Runners who strength train, sprint or race over varied terrain	Strong for strength; limited for pure endurance
Electrolytes	Replace sodium lost through sweat	Long or hot runs and runners with high salt losses	Situational
Iron	Correct a deficiency that can impair oxygen transport and performance	Runners with confirmed low iron status	Valuable only when clinically indicated
Vitamin D	Support normal bone, muscle and immune function	UK winters and people at greater risk of deficiency	Useful when intake or status is low

FIRST: WHAT COUNTS AS A SUPPLEMENT?

The term covers more than tablets. Supplements for runners can include vitamins, minerals, isolated nutrients, performance aids and sports foods such as gels, chews, drinks and protein powders.

The Australian Institute of Sport places carbohydrate products, electrolyte supplements, isolated protein, caffeine, dietary nitrate, creatine, iron and vitamin D in its Group A category. This means there is strong evidence for their use in specific sporting situations, not that every athlete should take all of them.

That distinction matters. A gel can be valuable during a marathon but unnecessary for an easy 30-minute run. Iron can transform how a deficient runner feels but provide no advantage – and potentially cause harm – when taken without need. Even an effective product becomes ineffective when it is used for the wrong reason.

1. CARBOHYDRATE GELS, CHEWS AND SPORTS DRINKS

If we judge value by the likelihood of helping a distance runner, carbohydrate products deserve to be near the top of the list.

Your body stores carbohydrate as glycogen in the muscles and liver, but those stores are limited. During prolonged running, consuming carbohydrate helps maintain blood glucose, supplies working muscles with additional fuel and can delay fatigue. Gels, chews and drinks are not inherently better than food; they are simply compact, portable and designed to be digested while moving.

How much carbohydrate do runners need?

As a general guide:

Runs lasting under 60 minutes: water and normal meals are usually enough.
Runs lasting 60–150 minutes: approximately 30–60g of carbohydrate per hour may be useful, depending on intensity and how well fuelled you were beforehand.
Runs lasting longer than 2.5–3 hours: up to 90g per hour from multiple carbohydrate sources, such as glucose and fructose, may benefit well-trained runners who have practised tolerating it.

These are targets, not compulsory quotas. A runner completing a relaxed 90-minute session may need less than someone racing hard for the same duration. Start lower, check how much carbohydrate is actually in each product and gradually train your gut during long runs.

Runner’s verdict: One of the most useful supplements for runners tackling long races – but it must be practised before race day.

2. CAFFEINE

Caffeine is one of the most consistently supported legal performance aids in endurance sport. It acts on the central nervous system and can increase alertness, reduce perceived effort and make a hard pace feel slightly more manageable.

A systematic review and meta-analysis found that moderate caffeine doses improved endurance time-trial performance on average, although responses varied considerably between individuals. That individual variation is important: caffeine can make one runner feel focused and powerful while leaving another shaky, anxious or desperate for the toilet.

How runners can use caffeine

Many runners respond to approximately 1–3mg per kilogram of body weight, taken around 30–60 minutes before exercise. Higher doses are not automatically more effective and are more likely to cause nausea, a racing heart, anxiety or disrupted sleep.

For a 60kg runner, 1–3mg/kg equals 60–180mg. The amount in coffee can vary widely, so a measured caffeine gel, gum or drink may be more predictable. Caffeine gum acts more quickly than a capsule, while a caffeinated gel can be saved for later in a long race.

Always test the exact product, dose and timing during training. If an evening race or late workout compromises your sleep, the small performance benefit may not be worth the recovery cost.

Runner’s verdict: Strong evidence, relatively inexpensive and potentially valuable for race day – but begin with a low dose.

3. DIETARY NITRATE OR BEETROOT JUICE

Beetroot juice has earned its place on start lines because it is naturally rich in nitrate. The body converts nitrate into nitric oxide, a molecule involved in blood flow, muscle contraction and the efficiency with which oxygen is used during exercise.

A 2025 umbrella review of 20 systematic reviews found that nitrate supplementation improved time-to-exhaustion performance, although the effects on time trials and other outcomes were mixed. Recreationally trained runners may be more likely to benefit than highly trained athletes, but there are responders and non-responders at every level.

How to take beetroot juice before running

Research protocols commonly provide around 5–9mmol of nitrate, or roughly 310–560mg, approximately two to three hours before exercise. Concentrated beetroot shots usually state their nitrate content on the label; an ordinary bottle of beetroot juice may not contain a standardised amount.

Avoid antibacterial mouthwash around the time of taking nitrate because oral bacteria play a role in converting it into a usable form. Expect harmless pink or red urine, and test the product in training because concentrated shots can upset some stomachs.

People with low blood pressure, kidney conditions or relevant medication should seek medical advice first.

Runner’s verdict: Worth trialling for a target race, especially if you are a recreational runner, but the benefit is not guaranteed.

4. PROTEIN POWDER

Protein powder does not possess a special recovery property that chicken, yoghurt, tofu, eggs, beans or milk lack. Its main advantage is convenience.

Running creates muscle damage and increases the need for tissue repair. Strength training adds another stimulus. Protein supports that adaptation, but a shake only helps when it contributes to an appropriate total intake. Evidence suggests protein supplementation can support adaptations to endurance training, although it is difficult to separate the effect of protein from the additional energy supplied in some studies.

Many endurance athletes can aim for roughly 1.2–1.6g of protein per kilogram of body weight per day, spread across meals and snacks. Needs may rise during heavy training, injury rehabilitation or an energy deficit. A serving providing approximately 20–30g of protein can be useful after training when a proper meal is not available.

A budget-friendly whey concentrate is suitable for most people who tolerate dairy. Soy is a complete plant protein, while blended pea-and-rice products can also work well. Check the protein per serving rather than judging a product by the size of its scoop or the claims on the front.

Runner’s verdict: Useful for convenience, not essential. Buy it if it helps you meet a genuine protein need – not because you believe every run requires a shake.

5. CREATINE MONOHYDRATE

Creatine is often associated with bodybuilding, but runners should not dismiss it automatically. By increasing phosphocreatine availability in muscle, creatine supports rapid energy production during short, powerful efforts.

For runners, that may support gym performance, strength development, repeated hill sprints, surges and finishing speed. It can therefore improve the training that sits around running, even if it does not directly improve steady-paced endurance.

That caveat matters. A 2023 meta-analysis found no significant overall improvement in endurance performance among trained participants taking creatine.[6] It can also increase body mass through additional water stored in muscle, which some runners notice more than others.

How much creatine should runners take?

The most researched form is creatine monohydrate. A simple dose of 3–5g daily will gradually saturate muscle stores; a loading phase is optional, not necessary. Consistency matters more than timing.

Some runners experience mild digestive discomfort, which may improve by taking a smaller dose with food. Anyone with kidney disease or another relevant medical condition should speak to a clinician before using it.

Runner’s verdict: Potentially valuable for runners who lift weights, sprint or want to preserve strength. Do not expect it to transform marathon pace by itself.

6. ELECTROLYTES

Electrolyte tablets are now treated as an everyday running essential, but many short, cool-weather runs do not create a meaningful need for them.

Sodium is the main electrolyte lost in sweat. The amount varies substantially with body size, temperature, pace, acclimatisation and individual sweat composition. Electrolytes are most likely to be helpful during prolonged running, hot conditions, high sweat rates or when clothes repeatedly dry with visible white salt marks.

For shorter sessions, water and normal food are usually enough. For longer races, sports drinks can be useful because they provide carbohydrate, fluid and sodium in one product. Drinking excessive plain water – or excessive electrolyte drink – can also be dangerous, so the goal is not to replace every drop of sweat or finish heavier than you started.

A practical strategy is to weigh yourself before and after selected training runs, account for fluid consumed, and observe how conditions affect your losses. Runners preparing for a hot marathon or ultra may benefit from an individual hydration plan developed with a sports dietitian.

Runner’s verdict: Valuable in specific conditions, not required for every easy 5K.

7. IRON

Iron is essential for haemoglobin production and oxygen transport, making low iron particularly relevant to endurance athletes. Runners may be more vulnerable because of menstrual blood loss, low energy availability, vegetarian or vegan diets, gastrointestinal losses and the repeated impact of foot strike.

Possible signs of iron deficiency include unusual fatigue, breathlessness, declining performance, poor concentration, feeling cold and struggling to recover. However, these symptoms have many possible causes, so self-diagnosis is unreliable.

A systematic review reported that iron deficiency can impair endurance performance in female athletes and that treatment can improve performance when deficiency is present. This does not mean that more iron creates more fitness in a runner whose status is already adequate.

Iron supplements can cause nausea, constipation and abdominal discomfort, and excess iron can be harmful. If you are concerned, ask a GP or appropriate clinician about blood testing and follow the dose and duration they recommend. Do not begin high-dose iron simply because training feels difficult.

Runner’s verdict: Potentially transformative when a deficiency is confirmed; inappropriate as a speculative performance supplement.

8. VITAMIN D

Vitamin D contributes to normal bone and muscle function. That makes it relevant to runners, particularly during the darker months when the skin produces less vitamin D from sunlight.

UK guidance recommends that adults consider a daily 10 microgram (400 IU) vitamin D supplement during autumn and winter. People with very little sun exposure, darker skin or other risk factors may be advised to take this amount throughout the year.

More is not necessarily better. High doses taken over time can cause excessive calcium to build up in the body and damage the kidneys and heart. Runners with a history of bone stress injuries, persistent musculoskeletal pain or suspected deficiency should discuss testing and treatment with a healthcare professional rather than copying a high-dose protocol online.

Runner’s verdict: A sensible seasonal consideration for UK runners, but megadoses will not create a performance boost in someone who is already sufficient.

WHAT ABOUT BETA-ALANINE AND SODIUM BICARBONATE?

Both have credible evidence in sport, but they are more relevant to short, high-intensity efforts than to steady distance running.

Beta-alanine increases muscle carnosine, which helps buffer acidity during hard efforts. It may be useful for middle-distance racing or repeated intense intervals, but several weeks of daily supplementation are required and tingling skin is a common side effect.

Sodium bicarbonate can improve performance during high-intensity efforts by increasing the body’s extracellular buffering capacity. However, the effective dose is large and notorious for causing bloating, nausea and diarrhoea. It should only be considered with expert guidance and extensive testing in training.

For the average half-marathon or marathon runner, carbohydrate availability, caffeine and a well-executed pacing plan are likely to offer far greater value.

SUPPLEMENTS RUNNERS PROBABLY DO NOT NEED

BCAAs

Branched-chain amino acids are widely marketed for recovery, but they do not contain all the essential amino acids required to maximise muscle protein synthesis. If you already consume enough complete protein, BCAAs add little.

MAGNESIUM FOR CRAMPS

Magnesium is important for normal muscle function, but routine supplementation has not been shown to prevent exercise-associated cramps in people who are not deficient. Cramps are complex and may relate to fatigue, pacing, conditioning and neuromuscular factors—not simply a missing mineral.

HIGH-DOSE ANTIOXIDANTS

More is not always better. Large, regular doses of isolated vitamins C and E may interfere with some of the signalling involved in adaptation to training. Colourful fruit and vegetables are the safer foundation.

FAT BURNERS AND “HARDCORE” PRE-WORKOUTS

These products often combine stimulants or proprietary blends, making their effects and doses difficult to predict. They can disturb sleep, raise heart rate, cause anxiety and carry a greater contamination risk. Faster running is built through training, recovery and adequate fuelling—not a thermogenic capsule.

COLLAGEN, TURMERIC AND OMEGA-3

All three have interesting areas of research, but the evidence is still emerging or mixed for routine use by healthy runners. They may have a place within an individual injury or nutrition plan, but none has been proven to make runners injury-proof.

HOW TO CHOOSE SUPPLEMENTS FOR RUNNERS SAFELY

Before buying anything, follow a simple process:

Identify the problem. Are you trying to fuel a marathon, correct a diagnosed deficiency or simply make recovery meals more convenient?
Check the foundations. Enough total energy, carbohydrate, protein, sleep and recovery will produce more value than most supplements.
Choose one product at a time. This makes it easier to judge whether it helps or causes side effects.
Use an evidence-based dose. More creates more risk, not necessarily more benefit.
Test it during training. Never introduce a new gel, caffeine dose or beetroot shot on race morning.
Record the result. Note the product, dose, timing, session, perceived benefit, sleep and stomach response.
Check the batch. Supplement labels can be inaccurate and products may become contaminated during manufacture. UK Anti-Doping advises athletes to assess the need and risk, then use batch-tested products to reduce – though never completely remove -the risk of prohibited substances.

THE BOTTOM LINE

The best supplements for runners are not the ones with the loudest marketing. They are the products that address a real need.

Carbohydrate gels and drinks can fuel long efforts. Caffeine has one of the strongest records for improving endurance performance. Dietary nitrate may provide a smaller advantage for some runners. Protein powder and creatine can support the recovery and strength work that makes better running possible.

Electrolytes become useful when sweat losses and conditions demand them. Iron and higher-dose vitamin D belong in a clinically informed plan, not an online shopping basket assembled after one bad run.

Build the foundation first. Add one evidence-based tool only when you understand what it is meant to do. A supplement should be the final one per cent of a sound running plan—not an attempt to replace the other 99.

SUPPLEMENTS: FREQUENTLY ASKED QUESTIONS

Do all runners need supplements?

No. Most runners can meet their everyday nutritional needs through a varied diet. Supplements are most valuable when they provide convenient fuel, correct a confirmed deficiency or offer a well-supported performance benefit for a specific session or race.

What is the best supplement for endurance running?

For long-distance running, carbohydrate consumed during exercise is usually the most practically valuable. Caffeine has some of the strongest evidence among traditional performance supplements. The best choice still depends on the event, the runner and what has been tested in training.

Should runners take electrolytes every day?

Usually not. Electrolytes are most useful during or after prolonged running, hot conditions or high sweat and sodium losses. Normal meals generally replace the electrolytes lost during shorter, cooler sessions.

Is creatine good for long-distance runners?

Creatine can support strength training and repeated high-intensity efforts, but research does not show a consistent direct improvement in endurance performance. Some runners also gain water weight, so its advantages and disadvantages should be considered individually.

Should female runners take iron?

Not automatically. Menstruating runners can be at greater risk of low iron, but supplementation should follow appropriate blood tests and professional advice. Taking iron when it is not needed can cause side effects and may be harmful.

Is magnesium worth taking for running?

Magnesium may be required if a runner has a diagnosed deficiency or inadequate dietary intake, but there is little reason to expect a performance or cramp-prevention benefit when magnesium status is already adequate.

Can runners take several supplements together?

Some products can be combined, but doing so increases the chance of excessive doses, duplicated ingredients and stomach problems. Introduce products separately in training, check labels carefully and seek professional advice if you use medication or have a health condition.

REFERENCES

Peeling, P., Castell, L. M., Derave, W., de Hon, O., & Burke, L. M. (2019). Sports foods and dietary supplements for optimal function and performance enhancement in track-and-field athletes. International Journal of Sport Nutrition and Exercise Metabolism, 29(2), 198–209. https://doi.org/10.1123/ijsnem.2018-0271
Jeukendrup, A. E. (2014). A step towards personalized sports nutrition: Carbohydrate intake during exercise. Sports Medicine, 44(Suppl 1), 25–33. https://doi.org/10.1007/s40279-014-0148-z
Southward, K., Rutherfurd-Markwick, K. J., & Ali, A. (2018). The effect of acute caffeine ingestion on endurance performance: A systematic review and meta-analysis. Sports Medicine, 48(8), 1913–1928. https://doi.org/10.1007/s40279-018-0939-8
Poon, E. T. C., Iu, J. C. K., Sum, W. M. K., Wong, P. S., Lo, K. K. H., Ali, A., Burns, S. F., & Trexler, E. T. (2025). Dietary nitrate supplementation and exercise performance: An umbrella review of 20 published systematic reviews with meta-analyses. Sports Medicine, 55(5), 1213–1231. https://doi.org/10.1007/s40279-025-02194-6
Lin, Y. N., Tseng, T. T., Knuiman, P., Chan, W. P., Wu, S. H., Tsai, C. L., & Hsu, C. Y. (2021). Protein supplementation increases adaptations to endurance training: A systematic review and meta-analysis. Clinical Nutrition, 40(5), 3123–3132. https://doi.org/10.1016/j.clnu.2020.12.012
Fernández-Landa, J., Santibañez-Gutierrez, A., Todorovic, N., Stajer, V., & Ostojic, S. M. (2023). Effects of creatine monohydrate on endurance performance in a trained population: A systematic review and meta-analysis. Sports Medicine, 53(5), 1017–1027. https://doi.org/10.1007/s40279-023-01823-2
Pengelly, M., Pumpa, K., Pyne, D. B., & Etxebarria, N. (2025). Iron deficiency, supplementation, and sports performance in female athletes: A systematic review. Journal of Sport and Health Science, 14, 101009. https://doi.org/10.1016/j.jshs.2024.101009
NHS. (n.d.). Vitamin D. NHS Vitamins and Minerals Guidance. Accessed 26 August 2026. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
UK Anti-Doping. (n.d.). Managing supplement risks. Accessed 26 August 2026. https://www.ukad.org.uk/athletes/managing-supplement-risks

Disclaimer: This article is for general informational and educational purposes only. It is not a substitute for personalised medical, nutritional or dietetic advice, diagnosis or treatment. Supplements may cause side effects, interact with medication or be unsuitable for certain health conditions. Always consult a GP, pharmacist or registered sports dietitian before beginning a new supplement – particularly if you take medication, are pregnant or breastfeeding, have an existing medical condition or suspect a nutrient deficiency. Iron and high-dose vitamin D should only be taken following appropriate testing and professional advice. Individual responses vary, and The Runner’s Journal does not endorse any specific product or brand.