Omega-3s Improve Athletic Performance

The scientific literature and the experience of many athletes leave little room for doubt: Omega-3s are an excellent tool for anyone looking to optimize post-exercise recovery. But their benefits for athletes appear to go further. Let's find out what is known about their ability to improve endurance performance.

Marine-derived Omega-3 supplements are widely used by athletes. They contain two molecules that are fundamental for physical and mental health: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), polyunsaturated fatty acids abundant in fish, krill and microalgae, well known for their anti-inflammatory properties.

The main reason they are used is to optimize post-exercise and post-competition recovery, but there is no shortage of data suggesting other possible applications. For example, several studies suggest the possibility of leveraging their properties to improve endurance performance. Let's find out, then, what evidence exists for their effectiveness as allies of recovery and endurance.

Omega-3, inflammation and recovery after exercise

Physical activity is associated with a physiological increase in inflammation and oxidative stress, and with alterations in immune defenses. The flow of oxygen into active muscles leads to the production of free radicals, promoting oxidative stress; reducing it can improve athletes' immune defenses and their performance. Inflammation must also remain limited over time; in this way it favors a good response to exercise, whereas if it becomes a chronic phenomenon it negatively affects recovery.

For their part, fish-derived Omega-3s (EPA and DHA) influence the immune system by improving post-exercise recovery; in particular, they have been associated with a reduction in:

• markers of inflammation, such as Tumor Necrosis Factor α (TNF-α);
• markers of muscle damage, such as myoglobin and creatine kinase;
• muscle soreness.

In addition, a study published in 2025 in Nutrients by a group of researchers led by Bojan Martinšek of the University of Ljubljana, Slovenia, concluded that short-term intake of high doses of Omega-3 in supplement form can regulate the activity of antioxidant enzymes precisely during endurance activity. The authors examined the effect of taking 9 grams of Omega-3 per day for 30 days on plasma Omega-3 levels and on the activity of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) in 21 more or less trained runners. Measurements were taken before and after training sessions consisting of 2,800 meters of running followed by 400 meters of sprinting. The supplements increased plasma EPA and DHA levels and reduced GPx and SOD levels in the trained runners.

Added to this evidence is data also suggesting that Omega-3s:

• promote muscle protein synthesis and an increase in lean mass;
• promote strength gains, influencing neuromuscular activity by modifying membrane composition and fluidity;
• reduce lipid accumulation in type I muscle fibers;
• improve metabolic flexibility.

Finally, in muscles, DHA appears to increase lipid oxidation, insulin sensitivity and glycolytic capacity.

Athletic performance: do Omega-3s improve it?

As for the possible effect on endurance performance, back in 2014, a group of researchers led by Fuminori Kawabata of the Human Life Science R&D Center in Tokyo, Japan, published in the pages of Bioscience, Biotechnology, and Biochemistry the results of a study according to which daily intake of EPA-rich fish oil supplements could improve, after just 8 weeks, movement economy — that is, the energy required to maintain a constant speed of movement during physical exercise — reducing perceived effort and thus increasing endurance.

The purpose of the research was to study the effects of EPA supplements on energy supply and movement economy during moderate-intensity aerobic exercise in untrained subjects.

Numerous previous studies had already shown that long-chain polyunsaturated fatty acids are a true boon for heart and circulation; they induce changes in the lipid composition of red blood cell, heart cell and muscle cell membranes, and are able to improve cardiac function. In addition, EPA and DHA (docosahexaenoic acid) can reduce blood viscosity, improving aerobic performance and increasing oxygen delivery to tissues, or reducing oxygen consumption by the heart without increasing cardiac workload.

Kawabata and colleagues recruited 20 healthy men with an average age of 23 who practiced sports at an amateur level. One group, chosen at random, received capsules containing 3.6 grams of EPA-rich fish oil every day for 8 weeks; the other group received the same amount of medium-chain fatty acids for the same period. At the end of the established period, the analyses conducted showed that EPA and DHA levels in the red blood cell membranes of those who had taken Omega-3 via fish oil had increased significantly (148% for EPA and 13% for DHA), while no increase was observed in the control group. In addition, the results of stress electrocardiogram tests showed a negative correlation between red blood cell EPA content and oxygen consumption during exercise; in other words, higher EPA content in erythrocytes was associated with lower oxygen consumption during muscular exercise tests.

These results had suggested that EPA could be a key factor for improved performance, and that EPA-rich fish oil supplements reduced the energy required for physical exercise and perceived effort in healthy subjects. Since there is a strong relationship between movement economy and endurance capacity, the authors of this study hypothesized that fish oil could also improve the latter. The mechanisms behind this effect had not, however, been clarified, and the possibility of using EPA-rich fish oil to enhance the benefits of physical rehabilitation remained to be confirmed. What do subsequent publications say on this subject?

In one of the few more recent studies focused specifically on subjects engaged in endurance training, published in Scientific Reports by Maja Tomczyk and colleagues in 2024, Omega-3s were associated with effects on tryptophan metabolism during training. 26 amateur runners, all men, underwent 12 weeks of endurance training; during the program they took Omega-3 supplements. Although it was not designed to demonstrate a direct increase in endurance performance (for example, in VO₂max), this study suggests interesting biological mechanisms for Omega-3s; in particular, the authors hypothesize a possible impact on processes related to central fatigue, recovery and adaptation to aerobic exercise.

Also in 2024, Diego Fernández-Lázaro and colleagues published in Nutrients the results of an analysis of 13 controlled studies involving healthy, physically active adults. The effects on endurance performance were found to be heterogeneous and not yet sufficient to definitively state that Omega-3s consistently improve performance. According to other analyses published the same year by Ryan Anthony and colleagues in Nutrition Research Reviews, the lack of definitive evidence for Omega-3's ability to improve it could be due to the difficulty of comparing results from studies of very variable duration, in which Omega-3s were used at very different dosages, in heterogeneous populations, and without an assessment of baseline levels in the body.

Allies against inflammation, possible help for performance

The analyses by Fernández-Lázaro and colleagues instead confirmed the ability of Omega-3s to:

• reduce certain markers of muscle damage;
• attenuate certain post-exercise inflammatory markers;
• improve certain indicators of oxidative stress.

In other words, the most convincing evidence concerns recovery and inflammatory response, and links Omega-3s to:

• a reduction in exercise-induced inflammation;
• less muscle damage;
• better post-training recovery;
• possible support for the metabolic adaptations of aerobic exercise.

New studies may confirm what is suggested by the data currently available on endurance performance, in particular:

• an increase in VO₂max;
• improved race times;
• increased resistance to fatigue during competition;
• a direct improvement in performance.

If you're interested in learning more about the benefits of Omega-3s in sport, listen to episodes 8, 12 and 20 of the podcast Perle di Benessere. It's available for free on Spotify and other major podcast platforms.

References

1. Anthony R, Macartney MJ, Heileson JL, McLennan PL, Peoples GE. A review and evaluation of study design considerations for omega-3 fatty acid supplementation trials in physically trained participants. Nutr Res Rev. 2024 Jun;37(1):1-13. doi: 10.1017/S095442242300001X

2. Fernández-Lázaro D, Arribalzaga S, Gutiérrez-Abejón E, Azarbayjani MA, Mielgo-Ayuso J, Roche E. Omega-3 Fatty Acid Supplementation on Post-Exercise Inflammation, Muscle Damage, Oxidative Response, and Sports Performance in Physically Healthy Adults-A Systematic Review of Randomized Controlled Trials. Nutrients. 2024 Jun 27;16(13):2044. doi: 10.3390/nu16132044

3. 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):2081-8. doi: 10.1080/09168451.2014.946392

4. Martinšek B, Skitek M, Kosjek T, Bedrač L, Benedik E. Effects of 30-Day High-Dose Omega-3 Fatty Acid Supplementation on Plasma Oxidative Stress Enzyme Activities in Recreational and Trained Runners: A Pilot Study. Nutrients. 2025 Sep 17;17(18):2985. doi: 10.3390/nu17182985

5. O'Connor E, Mündel T, Barnes MJ. Nutritional Compounds to Improve Post-Exercise Recovery. Nutrients. 2022 Nov 29;14(23):5069. doi: 10.3390/nu14235069

6. Smith GI 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 Feb;93(2):402-12. doi: 10.3945/ajcn.110.005611

7. Smith GI et al. Fish oil-derived n-3 PUFA therapy increases muscle mass and function in healthy older adults. Am J Clin Nutr. 2015 Jul;102(1):115-22. doi: 10.3945/ajcn.114.105833

8. Smith GI 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 Sep;121(6):267-78. doi: 10.1042/CS20100597

9. Tomczyk M, Bidzan-Wiącek M, Kortas JA, Kochanowicz M, Jost Z, Fisk HL, Calder PC, Antosiewicz J. Omega-3 fatty acid supplementation affects tryptophan metabolism during a 12-week endurance training in amateur runners: a randomized controlled trial. Sci Rep. 2024 Feb 19;14(1):4102. doi: 10.1038/s41598-024-54112-x

10. Żebrowska A et al. Omega-3 fatty acids supplementation improves endothelial function and maximal oxygen uptake in endurance-trained athletes. Eur J Sport Sci. 2015;15(4):305-14. doi: 10.1080/17461391.2014.949310