10 supplements for improved athletic performance

By Naveed Saleh, MD, MS, for MDLinx
Published May 6, 2020

Key Takeaways

Compared with the general US population, athletes are more likely to take ergogenic aids, which are dietary supplements marketed as enhancing endurance/strength, boosting exercise efficiency, increasing exercise tolerance, and attaining exercise goals more swiftly. Athletes—particularly elite athletes—use these supplements to prepare for exercise, help with recovery, and decrease chances of injury. But these supplements aren’t reserved for elite athletes. They may help you boost your performance and achieve your personal fitness goals.

Apparently, the National Institutes of Health’s Office of Dietary Supplements recognizes the importance of evaluating exercise supplements, and has published an evidence-based fact sheet detailing their efficacy, safety, and mechanisms. Per their analysis, these 10 supplements may help attain athletic goals. 

Beetroot/beet juice

This supplement dilates blood vessels in exercising muscle, boosts energy production, and decreases oxygen use. Although results are mixed, limited clinical trial data suggested that beetroot/beet juice could ameliorate athletic performance/endurance in time trials and time-to-exhaustion tests in swimmers, runners, rowers, and cyclists. Effects seem most pronounced in recreationally active non-athletes. At usual doses of two cups, no safety concerns are cited in the short-term.

Beta-hydroxy-beta-methylbutyrate (HMB)

HMB is purported to help stressed and damaged skeletal muscle cells re-establish function and structure, although clinical trials have yielded conflicting results about its efficacy. Nevertheless, HMB could hasten recovery from exercise that’s intense enough to damage muscle cells, such as a pulled hamstring or a torn rotator cuff. At a typical dose of 3 g/day for 2 months, no safety concerns have been reported.


This nutrient is found in beets, spinach, and whole-grain bread. Taken as a supplement, betaine is believed to boost creatine production, cellular water retention, and/or blood nitric-acid levels. Studies of bodybuilders and cyclists suggested that betaine may yield modest benefits for strength- and power-based performance, although evidence data from clinical trials are mixed. At a dosage of 2.5 g/day for up to 15 days, no side effects or safety concerns have been reported.

Branched-chain amino acids

The three branched-chain amino acids are leucine, isoleucine, and valine. Unlike other essential amino acids, these can be metabolized by mitochondria in skeletal muscle to yield energy for exercise. A small number of short-term clinical trials indicated that branched-chain amino acids might result in gains in muscle mass and strength during training. At a dosage of 20 g/day or less for up to 20 weeks, no safety concerns or adverse effects were reported.


This stimulant blocks activity of the sedative-like neuromodulator adenosine and decreases pain and perceived exertion. Clinical trials consistently support that when taken before physical activity, caffeine can improve performance, particularly in endurance activities, such as running, as well as in intermittent, long-duration activities like soccer. Caffeine is safe in dosages up to 400 mg to 500 mg/day in adults. Negative side effects include insomnia, nausea/vomiting, restlessness, tachycardia, arrhythmia, and death at an acute dose of 10 g to 14 g of pure caffeine.


This widely-studied supplement supplies muscles with energy for short, anaerobic bursts (eg, sprinting). A number of clinical trials support its benefit for high-intensity, intermittent activity, although these effects may vary by individual. Creatine has been shown in clinical trials to increase strength, work, and power for maximal-effort muscle contractions. Over time, it may aid athletes in adapting to training regimens. However, creatine’s benefits are negligible for endurance sports.

At a loading dose of 20 g/day for up to 7 days and 3 g to 5 g/day for up to 12 weeks, the supplement appears relatively safe. Nevertheless, it can result in weight gain due to water retention, and consumers have reported diarrhea, nausea, cramps, stiffness, and heat intolerance.


This important amino acid contributes nitrogen to various biochemical reactions and is a key player in metabolism and energy production. Limited research has indicated that it may enhance recovery/muscle strength and decrease soreness post-exercise. At a dosage of 45 g/day for 6 weeks, no safety concerns were reported. Dosages should be limited to 0.42 g/kg in those with infections, burns, intestinal diseases, and other serious illnesses.


Iron boosts uptake of oxygen, lowers lactate levels during exercise, and decreases heart rate. Although clinical trials have shown mixed results, some evidence indicates that this essential mineral improves work capacity when correcting for anemia. However, it remains to be elucidated whether iron is ergogenic in people with milder anemia. At 8 mg/day for healthy men and 18 mg/for healthy premenopausal women, no safety concerns have been noted. At more than 45 mg/day, negative side effects include constipation, gastric upset, abdominal pain, nausea, vomiting, and fainting.


Protein provides essential amino acids to build, maintain, and repair muscle tissue. Based on a wealth of clinical data, protein enhances muscle training response during exercise and recovery. Many athletes take protein after exercise, which is when it optimally reduces muscle protein breakdown, builds muscle, and enhances muscle oxygen use. At recommended intake levels of up to 2.0 g/kg body weight, no safety concerns have been reported.

Sodium bicarbonate

Commonly known as baking soda, this compound rids the body of hydrogen ions derived from intense muscle activity, thus decreasing metabolic acidosis and consequent fatigue. Short-term clinical trials have indicated that it might proffer minor to moderate improvements in performance for short-term and intermittent high-intensity activity—especially in trained athletes. At up to 300 mg/kg body weight, no safety concerns have been reported. Adverse effects include diarrhea, stomach pain, nausea, and vomiting.

Should you take these supplements? 

Which supplements are most popular? Male and female athletes take similar supplements, with women more likely to take iron and men more likely to take vitamin E, protein, and creatine.

In the aggregate, dietary supplements may contribute to athletic performance, according to the Office of Dietary Supplements.

“For any individual to physically perform at his or her best, a nutritionally adequate diet and sufficient hydration are critical,” stated authors from the Office of Dietary Supplements. “Athletes engaging in endurance activities lasting more than an hour or performed in extreme environments (e.g., hot temperatures or high altitudes) might need to replace lost fluids and electrolytes and consume additional carbohydrates for energy.”

They continued: “Even with proper nutritional preparation, the results of taking any dietary supplement(s) for exercise and athletic performance vary by level of training; the nature, intensity, and duration of the activity; and the environmental conditions.”

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