April 2020 Issue

Omega-3s for Sports Performance
By Densie Webb, PhD, RD
Today’s Dietitian
Vol. 22, No. 4, P. 18

An Overview of the Current Research and Strategies for Counseling Athletic Clients

Whether your clients are weekend warriors, twice-a-week yoga class attendees, or marathon runners, they may ask you about dietary supplements to improve performance, increase endurance, or build strength and muscle mass. You want to advise them wisely, but often that’s easier said than done, as there are hundreds, if not thousands, of supplements promising to build muscles and boost performance.

The omega-3 fatty acids DHA and EPA are among the most popular performance-enhancing supplements. This article will discuss how omega-3 supplementation may enhance sports performance, what the research says, and what experts advise in the four areas athletes may benefit from omega-3 supplementation.

How Omega-3s May Work
The applications of omega-3 supplementation for sports performance appear to be relevant for athletes involved in strength-, endurance-, and team-based activities.1 However, determining exactly how they work and how much omega-3s may benefit strength, endurance, and recovery is difficult.

According to Julie Stefanski, MEd, RDN, LDN, CSSD, CDCES, FAND, a spokesperson for the Academy of Nutrition and Dietetics and owner of Stefanski Nutrition Services in York, Pennsylvania, “Many of the studies on omega-3 supplementation cannot be compared head to head due to the differences in gender, age, type of omega-3s, source of the omega-3s, and the effect being researched.”

Omega-3 supplements vary widely in the amount and ratio of EPA to DHA, as do the types and amounts of exercise performed in studies.

Dietary omega-3 supplementation has been shown to inhibit the cyclooxygenase-2 pathway, which stimulates inflammation. The incorporation of omega-3s into cell membranes also alters cell membrane fluidity, modifying protein activities and cell function. Omega-3s have the potential to promote recovery from muscle-damaging exercise by increasing the structural integrity of muscle cell membranes. However, the mechanism that underpins improved oxygen efficiency with omega-3 supplementation is unclear.1

Research suggests that a minimum of two weeks of supplementation is needed for increased incorporation of omega-3s into muscle cells and that the incorporation of omega-3s continues to increase after four weeks of supplementation, with no plateau observed. More than four weeks of supplementation may be required to maximize muscle incorporation of omega-3s.1 However, Gordon Smith, PhD, an assistant professor of medicine at the Washington University School of Medicine in St. Louis, says, “as with most areas of sports performance, the improvement of any intervention is likely to be small in well-trained individuals.”

There’s evidence from studies in athlete populations to support the claim that omega-3 supplementation can facilitate muscle growth during resistance training and help preserve muscle mass when calories are restricted or during immobilization.

Studies have shown that supplementation for eight weeks with omega-3s (a combination of 1.86 g EPA and 1.5 g DHA) can increase the rate of muscle synthesis in young, middle-aged, and older adults.2,3 In older adults, six months of that level of supplementation resulted in a significant increase in thigh muscle volume and muscle strength.3

It’s been suggested that omega-3s work by switching on proteins involved in muscle protein synthesis, meaning they may contribute to increased muscle mass and strength. “In muscle cells grown in the lab, improvements in [muscle] protein metabolism were observed with EPA but not DHA treatment,” Smith says. “But there is no information as to whether the same is true in humans.”

As a result, it’s premature to recommend any specific EPA or DHA or ratios of EPA to DHA for athletic performance, he says.

At present, a limited number of studies have examined the influence of omega-3 ingestion on markers of energy metabolism and performance in endurance-trained individuals.1 There’s some scientific evidence suggesting that omega-3 supplementation may improve endurance capacity by reducing the oxygen cost of exercise. That may be because omega-3s act as vasodilators, which help increase the flow of oxygen into muscle during exercise, thereby increasing endurance.4

Dietary omega-3 supplementation also has been shown to reduce oxygen consumption, heart rate, and perceived exertion during endurance exercise.1 However, it’s unknown to what extent observed changes may improve objective measures of endurance.5,6

A three-week study of male athletes given 375 mg EPA, 510 mg DHA, and 230 mg docosapentaenoic acid (DPA) found that supplementation improved muscle function and fatigue compared with a placebo of olive oil.7 DPA is an omega-3 fatty acid similar in structure to EPA and DHA that’s linked to health benefits such as improved lipid metabolism and decreased inflammation.8

According to ConsumerLab.com, an independent provider of test results and information on dietary supplements, DPA is found in many fish oil supplements, at least in small amounts, even if it’s not listed on the label. However, DHA and EPA still comprise the major ingredients in omega-3 supplements.

Endurance athletes may experience an improvement in metabolic flexibility of muscle with EPA supplementation, which may translate to greater adaptability during endurance exercise.9 As for DHA, adult rats given DHA for nine weeks experienced improved endurance with exercise. Researchers have suggested that, based on additional research in rats, omega-3 supplementation may have the potential to help prevent the decline in exercise tolerance that occurs with age. More human studies are needed to assess the effect of omega-3s on human endurance and whether supplementation translates to improvements.4

Recovery from endurance exercise is important for reducing fatigue and improving performance. Oxidative stress occurs during exercise, and, while low levels of activity are necessary for muscle to adapt to exercise, strenuous exercise can lead to chronic inflammation, which can stress the body’s antioxidant systems.

Omega-3s are known for their anti-inflammatory properties. Although the findings have been mixed, some evidence suggests omega-3 supplementation can reduce muscle soreness and lessen oxidative damage to muscles.1

A study of 11 healthy men and women given 3 g omega-3s (2 g EPA plus 1 g DHA) for one week found a decrease in severe, delayed-onset muscle soreness following strenuous strength exercises.10 However, omega-3 supplementation may be less likely to aid recovery in those who regularly engage in endurance exercise, as their bodies adapt, resulting in less stress on the body’s antioxidant system.11

It’s difficult to accurately determine the effects of omega-3 supplementation on muscle recovery because of the different types of exercise used in studies, as well as differences in the dose and duration of omega-3 supplementation or ratio of EPA to DHA.9 

Leslie Bonci, MPH, RDN, CSSD, LDN, owner of Active Eating Advice and sports dietitian for the National Football League champion Kansas City Chiefs, says, “Omega-3s can be protective in attenuating muscle soreness and oxidative stress post exercise, but you need to look at overall recommendations for recovery post exercise—fluid, carbs, and protein rule.”

Omega-3s may help, she says, but that shouldn’t be to the exclusion of everything else.

According to the Brain Injury Institute, an estimated 1.6 million to 3.8 million sports- and recreation-related concussions occur in the United States each year. Among young people aged 5 to 18, the most common causes of concussions are bicycling, football, basketball, playground activities, and soccer. Football accounts for 60% of concussions among high school players.12

The role of omega-3s in growth and maintenance of neurons is well known. Studies, mostly in animals, suggest that omega-3 supplementation may be effective both in the prevention and treatment of traumatic brain injury (TBI) resulting from concussions.

One study found that rats given preinjury dietary supplementation with fish oil (6% of rat chow) experienced a small improvement in performance in a maze after TBI.13 “Obviously, traumatic brain injury cannot be induced in humans, so the ability to study the effects in humans is lessened compared to other uses of omega-3s,” Stefanski says.

There was, however, one randomized, double-blinded, placebo-controlled human study of 81 National Collegiate Athletic Association Division I football athletes, who were given either 2, 4, or 6 g per day of DHA or a placebo for 189 days. It was the first large-scale study to examine potential preventive use of DHA in American football athletes. Athletes taking DHA experienced decreased concentrations of a specific biomarker of head trauma compared with those given placebo.14 

Based on current knowledge, omega-3 supplementation has the potential to play a role in improving training adaptation, exercise recovery, injury prevention, and subsequent performance in athlete populations. At the very least, the evidence suggests that increasing omega-3s in the diet or via a supplement isn’t harmful.1

“For athletes, focusing on increasing omega-3 fats, which are beneficial for reducing inflammation, and reducing omega-6 fat intake—[which], when consumed in excess, can increase inflammation—is an easy swap to support repair of the cell damage experienced in intense physical activity and training,” Stefanski says.

The International Olympic Committee recommends a dosage of about 2 g per day of omega-3 fatty acids, either from supplements or fatty fish, but doesn’t specify amounts of DHA or EPA or a ratio of the two.15 Bonci says that unless omega-3s are indicated for hypertriglyceridemia or other medical conditions, individuals shouldn’t take more than 2 g of supplemental omega-3s per day. She also emphasizes that fatty fish, such as salmon, mackerel, sardines, anchovies, and tuna, which is rich in omega-3s, confers the added advantage of protein plus vitamins and minerals over omega-3 supplements. The 2015–2020 Dietary Guidelines for Americans recommend consuming fish twice per week (a total of at least 8 oz).

Stefanski recommends athletes use a stepwise approach of first increasing food sources of omega-3s and then discussing supplementation at a low dose with either their primary care provider or a dietitian to ensure there are no contraindications with supplementing.

While athletes value the research on omega-3s, it also may benefit other populations, such as patients in physical therapy and cardiac rehabilitation, as well as healthy casual exercisers; muscle soreness, which if left unchecked, can slow progress when adapting to a new exercise program.4

Bonci says research on omega-3s also is strong for improved pulmonary function, decreased risk of upper respiratory infections, and decreased inflammation—all of which benefit athletes and nonathletes alike.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.


1. Philpott JD, Witard OC, Galloway SDR. Applications of omega-3 polyunsaturated fatty acid supplementation for sport performance. Res Sports Med. 2019;27(2):219-237.

2. Smith GI, Atherton P, Reeds DN, et al. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial. Am J Clin Nutr. 2011;93(2):402-412.

3. Smith GI, Atherton P, Reeds DN, et al. Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women. Clin Sci (Lond). 2011;121(6):267-278.

4. La Guen M, Chaté V, Hininger-Favier I, et al. A 9-wk docosahexaenoic acid-enriched supplementation improves endurance exercise capacity and skeletal muscle mitochondrial function in adult rats. Am J Physiol Endocrinol Metab. 2016;310(3):E213-E224.

5. Kawabata F, Neya M, Hamazaki K, Watanabe Y, Kobayashi S, Tsuji T. Supplementation with eicosapentaenoic acid-rich fish oil improves exercise economy and reduces perceived exertion during submaximal steady-state exercise in normal healthy untrained men. Biosci Biotechnol Biochem. 2014;78(12):2081-2088.

6. Peoples G, McLennan P, Howe PR, Groeller H. Fish oil reduces heart rate and oxygen consumption during exercise. J Cardiovasc Pharmacol. 2008;52(6):540-547.

7. Lewis EJ, Radonic PW, Wolever TM, Wells GD. 21 days of mammalian omega-3 fatty acid supplementation improves aspects of neuromuscular function and performance in male athletes compared to olive oil placebo. J Int Soc Sports Nutr. 2015;12:28.

8. Byelashov OA, Sinclair AJ, Kaur G. Dietary sources, current intakes and nutritional role of omega-3 docosapentaenoic acid. Lipid Technol. 2015;27(4):79-82.

9. Da Boit M, Hunter AM, Gray SR. Fit with good fat? The role of n-3 polyunsaturated fatty acids on exercise performance. Metabolism. 2017;66:45-54.

10. Jouris KB, McDaniel JL, Weiss EP. The effect of omega-3 fatty acid supplementation on the inflammatory response to eccentric strength exercise. J Sports Sci Med. 2011;10(3):432-438.

11. Bloomer RJ, Larson DE, Fisher-Wellman KH, Galpin AJ, Schilling BK. Effect of eicosapentaenoic and docosahexaenoic acid on resting and exercised-induced inflammatory and oxidative stress biomarkers: a randomized, placebo-controlled, cross-over study. Lipids Health Dis. 2009;8:36.

12. What is a concussion? Brain Injury Research Institute website. http://www.protectthebrain.org/Brain-Injury-Research/What-is-a-Concussion-.aspx. Accessed January 9, 2020.

13. Wang T, Van KC, Gavitt BJ, et al. Effect of fish oil supplementation in a rat model of multiple mild traumatic brain injuries. Restor Neurol Neurosci. 2013;31(5):647-659.

14. Oliver JM, Jones MT, Kirk KM, et al. Effect of docosahexaenoic acid on a biomarker of head trauma in American football. Med Sci Sports Exerc. 2016;48(6):974-982.

15. Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52(7):439-455.