Muscle & Strength Builders

Fish Oil and Muscle Growth

Already championed for its health benefits, fish oil solidifies its rep as a powerful lean-muscle supplement.

If you had to put your supplement budget into a pie chart, a large wedge would likely be devoted to protein, with a smattering of smaller slices dedicated to pre-workouts and a few ancillary supps. But if you want a do-it-all supplement with a proven pedigree and a growing body of favorable research, then it’s time to give fish oil a bigger piece of the pie. Over the last several years, the research findings supporting the health benefits of fish oil have been astounding. What you may already know: The omega-3 fatty acids found in cold-water fish can reduce inflammation, boost cardiovascular health, increase the efficiency of the heart during exercise and maintain healthy blood lipid profiles. What you may not know: Fish oil has also been shown to increase fat metabolism and lean mass gain. Better overall health and vitality and bigger, leaner muscles? We know it smells — wait for it — fishy, but fish oil really is all it’s cracked up to be and then some. Let’s take a walk through the research lab for an itemized account of this supplement’s many benefits.

1. Fish oil improves exercise efficiency

Scientists from Australia showed that fish oil decreases the amount of work the heart and muscles have to do during maximal cycling exercise. They reported that fish oil supplements reduced not only the heart rate (including peak heart rate) during incremental exercise to exhaustion but also steady-state submaximal exercise heart rate, whole-body oxygen consumption and the oxygen requirements of the heart. In light of the data, it seems that fish oil makes the heart and skeletal muscles contract more efficiently during moderate- to high-intensity exercise. Along similar lines, in a more recent study published in Bioscience, Biotechnology, and Biochemistry, Japanese researchers hypothesized that since docosahexaenoic acid (DHA) and eico-sapentaenoic acid (EPA) in fish oil act as blood thinners, taking fish oil may improve blood flow and oxygen supply to tissues, thereby increasing exercise performance. In this double-blinded and placebo-controlled study, 20 fit, college-aged male volunteers took either 3.6 grams of fish oil or a placebo split into three daily doses for eight weeks. Before and after supplementation, subjects completed a series of VO2 max (maximum aerobic fitness) tests and submaximal exercise tests. As predicted, the researchers found that fish oil supplements increased red blood cell EPA and DHA content and decreased oxygen consumption during steady-state submaximal exercise. They also reported that subjects who took fish oil had reduced measures of perceived exertion, meaning the exercise felt easier. Study authors concluded that fish oil supplementation improves exercise efficiency, which may also promote greater exercise endurance capacity.

2. Fish oil promotes anabolism

It gets better. Recent evidence shows that taking omega-3 fatty acids like those found in fish oil in the face of hyperaminoacidemia (which occurs when you drink a whey protein isolate shake) and hyperinsulinemia (which occurs when you ingest fast-digesting carbohydrates like dextrose) leads to a considerable increase in anabolism. In a study published in Clinical Science, scientists from Washington University School of Medicine (St. Louis) evaluated the anabolic effects of taking omega-3 fatty acids under conditions of hyperaminoacidemia and hyperinsulinemia. Nine healthy men and women ages 25 to 45 were subjected to stable-isotope tracer infusions and muscle biopsies before and after eight weeks of omega-3 supplementation. The infusions were used to evaluate the rate of muscle protein synthesis and anabolic signaling under baseline conditions and during insulin and amino acid infusion. Interestingly, taking omega-3s alone did not affect anabolism, but when they were combined with hyperaminoacidemia and hyperinsulinemia there was a 34 percent increase in the muscle protein fractional synthesis rate and a 50 percent increase in major anabolic signaling factors. Of particular note, muscle biopsies revealed an increase in muscle protein concentration and muscle cell size.

3. Fish oil improves body composition

Scientists from Gettysburg College in Pennsylvania conducted research that examined the effects of fish oil supplementation on resting metabolic rate (RMR), body composition and cortisol levels in healthy men and women. In this double-blinded study, baseline (pre-supplementation) measures of RMR, body composition (using a Bod Pod) and cortisol (from saliva) were completed after fasting. Subjects were randomly put into two groups and received four capsules (4 grams) per day of either fish oil containing only omega-3 fatty acids or safflower oil containing only omega-6 fatty acids. They took two capsules each with breakfast and dinner for six weeks, with no further changes made to their diets. At the end of the study, subjects returned to the lab to be retested for RMR, body composition and cortisol levels. The researchers reported that those who took the omega-3 fish oil supplement had a more than 1-pound increase in lean mass and a 1-pound loss in fat mass, whereas the omega-6 safflower oil group saw no changes. No changes were found in RMR or body mass in either group, but cortisol levels tended to be lower in those taking fish oil. This tendency correlated with that group’s increase in lean mass and decrease in fat mass. This is an interesting study, and the data suggest that changes in body composition with supplemental fish oil are at least partially due to the positive impact of omega-3 fatty acids on cortisol levels. Yet given the significant changes in body composition in the fish oil group, it’s perplexing that there was no change in RMR. Regardless, the data are intriguing and provide solid support for the use of fish oil in those looking to maximize muscular gains while staying lean.

Teaching Men to Fish: To reap all the health and exercise benefits of fish oil, take 1 to 3 grams of high-DHA and -EPA fish oil with breakfast, lunch and dinner. On training days, take one dose with your postworkout protein (25 to 50 grams) and dextrose (25 to 50 grams) shake.