Omega-3 is a family of n-3 polyunsaturated fatty acids (PUFAs), which have been used to treat a wide variety of chronic diseases, due mainly to their antioxidant and anti-inflammatory properties, among others. In this context, omega-3 could be post-exercise recovery agent and sports supplement that could improve performance by preserving and promoting skeletal muscle mass and strength. No conclusive evidence, however, exists about the potential effects of omega-3 on post-exercise biomarkers and sports performance in physically healthy adults. Based on the PRISMA in Exercise, Rehabilitation, Sports Medicine, and Sports Science (PERSiST) guidelines, we systematically reviewed studies indexed in Web of Science, Scopus, and Medline to assess the effects of omega-3 on post-exercise inflammation, muscle damage, oxidant response, and sports performance in physically healthy adults. The search was performed on original articles published in the last 10 years up to 5 May 2024, with a controlled trial design in which omega-3 supplementation was compared with a control group. Among 14,971 records identified in the search, 13 studies met the selection criteria. The duration of the interventions ranged from 1 day to 26 weeks of supplementation and the doses used were heterogeneous. Creatine kinase (CK) and lactate dehydrogenase (LDH) were significantly higher (p < 0.05) in the control group in 3 of the 4 studies where these markers were analyzed. C-reactive protein (CRP) was significantly higher (p < 0.05) in the control group of 2 of the 13 studies where this marker was analyzed. The delayed onset muscle soreness (DOMS) gave mixed results. Interleukin 6 (IL-6) showed improvements with supplementation, but tumor necrosis factor-α (TNF-α) displayed no differences. The consumption of n-3 PUFAs improved some indicators of oxidative stress such as reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. Additional evidence is needed to establish clear recommendations regarding the dose and length of n-3 PUFA supplements. These may benefit the post-exercise inflammatory response, mitigate muscle damage, and decrease oxidative stress caused by exercise. However, studies did not evaluate omega-3 status at baseline or following supplementation and therefore the observations must be treated with caution
