Top 10 Endurance Supplements, Ranked by Evidence (2026)

The best supplements for endurance athletes fall into two groups: a small set with strong performance evidence (dietary nitrate from beetroot, creatine, beta-alanine, caffeine, and sodium bicarbonate, the five recognized by the International Olympic Committee) and a foundational set that supports the engine behind them (protein, iron, electrolytes, omega-3, and vitamin B12). Most marketed endurance supplements fall outside both groups. Prioritize the evidence-backed performance aids first, then close nutritional gaps, and treat everything else as optional.

Not every endurance supplement carries the same weight of evidence. The table below tiers the ten covered in this guide by how strong the human performance data actually is, so you can prioritize spend before reading the detail on each.

Here are the ten, ordered by how strong the human performance evidence actually is, so the list matches the table above rather than contradicting it.

1. Dietary Nitrate (Beetroot)

Dietary nitrate has the strongest evidence of any endurance-specific supplement. More than 30 randomized controlled trials show a 1 to 3 percent reduction in the oxygen cost of submaximal exercise at 300 to 600 mg of nitrate, taken 2 to 3 hours before the effort. It works by raising nitric oxide, which dilates blood vessels and improves aerobic economy.

The practical problem is dose verification: nitrate content varies roughly 100x across beet products, and most labels disclose only the weight of dried root. Two options stand out at the performance end of the market. Momentous Beet is NSF Certified for Sport, meaning each batch is third-party tested for banned substances, which matters if you are subject to testing. Beetroot Pro® pre-workout beet powder uses patented betaine nitrate with a disclosed 1,400 mg per serving, yielding 160 mg of dietary nitrate, and no added sugar. See a full comparison of both.

2. Creatine

Creatine is the best-evidenced supplement for the repeated hard efforts inside an endurance race: the climbs, the bridges, the finish. It increases phosphocreatine stores so ATP regenerates faster between surges. Standard dosing is 3 to 5 g per day, and stores take roughly 28 days to saturate without a loading phase.

Creatine may also help improve endurance by reducing muscle fatigue across efforts lasting longer than 30 seconds. Because both creatine and beta-alanine require consistent daily dosing over weeks rather than a race-day dose, athletes often take them together. Endurance360® combines both alongside electrolytes and adaptogens (cordyceps, rhodiola) designed for that multi-week loading period.

3. Beta-Alanine

Beta-alanine raises muscle carnosine, the buffer that slows the pH drop during hard efforts. The published dosing range is 3.2 to 6.4 g per day for 4 to 6 weeks, and the benefit concentrates in efforts lasting roughly 1 to 4 minutes: VO2 max intervals, criterium surges, and 5K to 10K racing rather than steady long-distance work.

Beta-alanine supplementation does nothing on the day you take it. Carnosine accumulates slowly, so a single dose before a race is wasted; only weeks of consistent daily intake raise the buffer. The harmless skin tingling some athletes notice confirms absorption, not effect. Most commercial endurance capsules sit well under the published range: Optygen HP discloses 1,500mg and Endurance360 places its beta-alanine inside a 2,000mg blend it shares with creatine, so reaching saturation on either means adding standalone powder. The Endurance360 vs Optygen HP comparison, the Xendurance Extreme Endurance review and the SportLegs alternative breakdown each work through one of these labels in full.

4. Caffeine

Caffeine is the most reliably ergogenic supplement in sport and the cheapest. The evidence-based dose is 3 to 6 mg per kg of body weight, taken 30 to 60 minutes before the effort. It works primarily by lowering perceived exertion, so the same pace feels easier, with benefits across efforts from a few minutes to multi-hour races.

Higher doses do not improve the effect and increase the risk of jitters, elevated heart rate, and disrupted sleep. Habitual coffee drinkers still respond, though tolerance blunts the effect somewhat.

The fifth supplement in the strong-evidence tier is sodium bicarbonate, which is not in this top ten because its GI tolerability makes it impractical for most athletes outside targeted middle-distance events. All five are covered in the IOC consensus on supplements for endurance athletes.

5. Protein

Protein is foundational rather than ergogenic: it does not make you faster on the day, but insufficient intake blunts the adaptation you are training for. Endurance athletes should target 1.4 to 2.0 g per kg of body weight per day from total diet, with supplementation only to close the gap food leaves.

Endurance exercise breaks down muscle protein for energy, and adequate intake supports repair and adaptation between sessions. It also helps with appetite control during heavy training blocks.

6. Iron

Iron carries oxygen, so a deficiency directly limits endurance, but supplementing without a deficiency provides no benefit and carries real risk. Test before you supplement. Endurance athletes at highest risk are female athletes, vegetarians and vegans, and anyone with heavy training loads or gastrointestinal blood loss.

Dose and formulation should follow a blood test and a physician's guidance, not a label recommendation. Iron overload is genuinely harmful, which separates iron from most items on this list.

7. Electrolytes (Sodium, Potassium, Magnesium)

Electrolytes, such as sodium, potassium, and magnesium, maintain fluid balance and neuromuscular function during long efforts. The correct intake is matched to your own sweat rate and sweat sodium concentration, not to a fixed number, because sweat sodium varies several-fold between athletes.

Imbalances contribute to cramping, premature fatigue, and in extreme cases hyponatremia. Sweat rate testing is a better guide than any generic hourly target.

8. Omega-3 (EPA and DHA)

Omega-3 fatty acids support recovery through their anti-inflammatory effect rather than by improving performance directly. Typical supplementation is 1 to 3 g per day of combined EPA and DHA, most useful for athletes who eat little oily fish. The performance evidence is modest; the recovery and general health evidence is stronger.

9. Vitamin B12

Vitamin B12 supports red blood cell formation and energy metabolism, so a deficiency causes fatigue that looks like poor fitness. Like iron, it is worth supplementing only when diet or a blood test indicates a shortfall. Vegetarians, vegans, and older athletes are the groups most likely to be low.

10. BCAAs, Glutamine, and High-Dose Antioxidants

These are grouped together because they share a problem: heavy marketing and weak endurance performance data. BCAAs (for runners) and glutamine are sold for recovery and reduced soreness, but the measurable performance effect in well-fed athletes is small to absent once total protein intake is adequate.

High-dose antioxidant supplementation (vitamins C and E) is the clearest case for caution: the oxidative stress of training is part of the adaptation signal, and blunting it with large doses can interfere with the training response you are chasing. These should be the last place an endurance athlete spends. The same evidence-first lens applies to newer trends like lactate energy gels, where the hype is currently ahead of the data.

What Ergogenic Aid May Help an Endurance Athlete?

For most endurance athletes the shortlist is dietary nitrate, caffeine, creatine, and beta-alanine, with sodium bicarbonate as a situational fifth. Everything else on a supplement shelf is either foundational nutrition that corrects a deficit or marketing ahead of the data. Start with the four, then fix nutritional gaps, then stop.

PubMed: The most popular supplements or ergogenic aids for the endurance athlete are caffeine, antioxidants, erythropoietin, and the dietary practice of carbohydrate loading. Caffeine and carbohydrate loading have the most evidence-based support of being both ergogenic and safe. Erythropoietin is ergogenic but unsafe, and is banned by all major sport-sanctioning bodies, and antioxidants have potential but warrant further study. Pyruvate is not ergogenic.

The best endurance supplements are readily available through various products. Some are crucial for basic physical functions and others have a strong correlation with sports performance. It's important to note that supplements should not be used as a replacement for a healthy and balanced diet.

Always consult with a healthcare professional before starting any supplement regimen. For a running-specific version of this list organized by training phase rather than evidence tier, see Best Supplements for Runners.

Endurance360® contains Beta Alanine, Creatine Monohydrate, Cordyceps & Rhodiola.

Beetroot Pro® contains beet extract, potassium, magnesium, sodium and Vitamin B12.

FDA disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product and website content is not intended to diagnose, treat, cure, or prevent any disease.

Sources:

1. Protein: Tarnopolsky, M. A. (2004). Protein and endurance exercise. Journal of Sports Sciences, 22(1), 65-70.

2. Beta-Alanine: Derave, W., Everaert, I., Beeckman, S., Baguet, A., & Achten, E. (2010). Beta-alanine supplementation improves sprint performance in endurance cycling. Medicine and Science in Sports and Exercise, 42(6), 1162-1168.

3. Creatine: Rawson, E. S., Volek, J. S., & Craig, S. A. (2003). Performance and muscle fiber adaptations to creatine supplementation and heavy resistance training. Medicine and Science in Sports and Exercise, 35(3), 456-463.

4. Iron: Burke, L. M., & Deakin, V. (2015). Clinical sports nutrition (5th ed.). Sydney: McGraw-Hill Education.

5. Branched-Chain Amino Acids (BCAAs): Shimomura, Y., Yamamoto, Y., Bajotto, G., Sato, J., Murakami, T., Shimomura, N., & Kobayashi, H. (2006). Nutritional and physiological aspects of branched-chain amino acid supplementation for athletes. Journal of Nutrition, 136(1), 274S-278S.

6. Nitrate: Larsen, F. J., Weitzberg, E., Lundberg, J. O., & Ekblom, B. (2010). Effects of dietary nitrate on blood pressure in healthy volunteers. The New England Journal of Medicine, 363(19), 2027-2034.

7. Electrolytes: Armstrong, L. E., & Casa, D. J. (2005). American College of Sports Medicine position stand: Exercise and fluid replacement. Medicine and Science in Sports and Exercise, 37(2), e3-e7.

8. Antioxidants: Powers, S. K., Jackson, M. J., & Dodd, S. L. (2007). Exercise-induced oxidative stress: Cellular mechanisms and impact on muscle force production. Physiological Reviews, 87(4), 1243-1276.

9. Caffeine: Doherty, M., & Smith, P. M. (2004). Effects of caffeine ingestion on exercise testing: A meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 14(6), 626-646.

10. Glutamine: Varnier, M., Leese, G., Thompson, J., & Rennie, M. J. (1995). Stimulatory effect of glutamine on glycogen accumulation in human skeletal muscle. American Journal of Physiology-Endocrinology And Metabolism, 269(6), E309-E315.

Master the Protocol: Read our definitive guides on VO2 Max Supplements, Beta-Alanine, the 14-Day Loading Protocol, and estimate your current ceiling with the free VO2 max calculator.

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.