Does Fish Oil Help Athletes Gain Muscle?
In the ultra-competitive world of top performing athletes, an extra percent gain makes all the difference. While hard-work and dedication is the typical formula for success in sports (and life), some are looking for other alternatives to “hack” their progress. Fish oil is a popular supplement that just about every athlete is taking. Most take it for its anti-inflammatory and heart health properties, but my interest is in its effect on muscle growth. I did some digging and here’s what I came up with.
Study #1 - Protein Synthesis using Muscle Biopsy
This study was 8 weeks long looking at the effects of fish oil supplementation and muscle protein synthesis rates. The study used a muscle biopsy (took a small sliver of muscle tissue) to measure muscle protein synthesis rate. Muscle protein synthesis is associated with building skeletal muscle. To build muscle you must have a net positive balance between muscle protein synthesis and break down. The population consisted of 19 men. Group 1 consisted of 9 subjects at an average age of 24 years. Group 2 consisted of 10 subjects at an average age of 21 years. One group received 5g of fish oil, the other 5g of coconut oil. The participants did not follow a training protocol however it wasn't stated if they trained or not. There were no significant differences in MPS between groups for time.
McGlory C, Wardle SL, Macnaughton LS, Witard OC, Scott F, Dick J, Bell JG, Phillips SM, Galloway SD, Hamilton DL, Tipton KD. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men. Physiol Rep. 2016 Mar;4(6):e12715. doi: 10.14814/phy2.12715. PMID: 27009278; PMCID: PMC4814892.
Study #2 - protein sythesis using Dual Energy X-ray
This study took 12 weeks long looking at the effects of fish oil supplementation and muscle protein synthesis rates. The study used a DEXA or dual energy X-ray absorptiometry to measure body composition. The DEXA is the gold standard when measuring body composition. There were 23 subjects all over 65 years old. One group received 3g of fish oil, the other 3g of a placebo. The participants did follow a 3 day a week whole body resistance training protocol. There were no significant differences between groups for time in lean tissue mass.
Cornish, S. M., Myrie, S. B., Bugera, E. M.,Chase, J. E., Turczyn, D., & Pinder, M. (2018). Omega-3 supplementation with resistance training does not improve body composition or lower biomarkers of inflammation more so than resistance training alone in older men. Nutrition Research. https://doi.org/10.1016/j.nutres.2018.09.005
Study #3 - body composition using Skin Fold Caliper
28 day study looking at the effects of fish oil supplementation and body composition. The study used a 4 site skinfold caliper assessment. The skin fold caliper is not the gold standard when it comes to body composition assessments. There were 15 subjects with an average age of 23±5 years. One group received 1.4g of fish oil, the other 1g of a placebo (safflower oil). The participants self reported their exercise with no statistical significance between groups. There was a significant difference within-group for lean mass. The placebo group increased 0.9lbs while the omega-3 group increased 2lbs, however the fish oil group increased total body weight by 2.2lbs while the placebo remained the same weight. Although the fish oil group gained more lean mass they also increased total body weight; meaning they were in a caloric surplus which promotes a more anabolic (muscle building) state. While the placebo group remained the same weight while adding muscle mass; meaning they were in a neutral caloric intake which is less anabolic when compared to a caloric surplus.
Crestani, D.M., Bonin, É.F.R., Barbieri, R.A. et al. Chronic supplementation of omega-3 can improve body composition and maximal strength, but does not change the resistance to neuromuscular fatigue. Sport Sci Health 13, 259–265 (2017). https://doi.org/10.1007/s11332-016-0322-9
Study #4 - Caloric Restricion using Dual Energy X-ray
6 week study looking at the effects of fish oil supplementation with caloric restriction. The study used a DEXA or dual energy X-ray absorptiometry to measure body composition. The DEXA is the gold standard when measuring body composition. The population consisted of 20 men with an average age of 23±1 years old. These men were already resistance trained. The study supplemented 4g of fish oil. There were two randomized groups one receiving 4g of fish oil the other a placebo. There were no significant differences in Fat Free Mass.
Philpott JD, Bootsma NJ, Rodriguez-Sanchez N, Hamilton DL, MacKinlay E, Dick J, Mettler S, Galloway SDR, Tipton KD, Witard OC. Influence of Fish Oil-Derived n-3 Fatty Acid Supplementation on Changes in Body Composition and Muscle Strength During Short-Term Weight Loss in Resistance-Trained Men. Front Nutr. 2019 Jul 16;6:102. doi: 10.3389/fnut.2019.00102. PMID: 31380384; PMCID: PMC6652803.
My Interpretation
Fish Oil is known as an Omega-3 polyunsaturated fatty acid. Omega-3s are considered essential fatty acids because they can't be synthesized in the body. Fish Oil has both DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). EPA is thought to inhibit the NF-kB pathway which has been shown to promote muscle atrophy. Inhibition of the NF-kB pathway would theoretically limit muscle atrophy (breakdown). Fish oil seems to help preserve muscle mass during catabolic situations (net negative balances aka. using more than you are taking in).
Overall I believe the literature does not support the idea that fish oil significantly improves muscle mass. However there are proposed mechanistic pathways that fish oil may have a protective component when looking at muscle. As of right now it looks like proper exercise and nutrition seem to be some of the best ‘supplements’ to prevent/limit muscle atrophy and in most cases promote muscle gain. There are numerous other health benefits and I believe this is a great supplement when not consumed regularly in the diet. Always consult your doctor before adding a supplement to your diet.