Omega-3 fatty acids aren’t just for the brain and heart—they also preserve and help increase muscle mass due to their anti-catabolic and anabolic effects.

A recent meta-analysis revealed that combining omega-3 supplementation with exercise significantly boosts cardiometabolic health outcomes compared to exercise alone:

• Reduces body fat (~1 kg reduction)
• Improves triglyceride levels
• Decreases inflammation
• Lowers blood pressure (4 mmHg reductions in systolic and diastolic pressures)
• Enhances lower-body strength

Some of the benefits were modest—such as the reduction in body fat mass—while others were large and clinically significant—like the reductions in both systolic and diastolic blood pressure. 

This was achieved with a dose of omega-3s ranging from 1–4.5 grams per day.

Supplementing with omega-3 fatty acids (and eating a diet high in omega-3-containing foods) is something you should already be doing to support your cardiovascular and brain health. The good news is that this essential nutrient is also helping you get more out of your exercise training regimen.

How Omega-3s Affect Muscle

Work by Dr. Chris McGlory (who I interviewed on episode #81 of the FoundMyFitness podcast) and others has highlighted a suite of effects that may be attributable to omega-3 fatty acids:

• Omega-3s reduce anabolic resistance within the context of disuse atrophy—preventing nearly half the loss of muscle and enhancing the return of skeletal muscle mass to baseline levels after weeks of immobilization.
• Omega-3s enhance muscle protein synthesis (MPS) by improving the body’s response to insulin and amino acids.
• Omega-3s have anti-inflammatory effects that may also lessen the severity of sarcopenia, a condition driven by chronic low-grade inflammation.
• Omega-3 supplementation increases the omega-3 fatty acid composition of skeletal muscle membranes and alters mitochondrial bioenergetics.

The effects of omega-3s extend beyond preventing muscle disuse atrophy—in combination with resistance training, they promote greater gains in muscle strength and functional performance in older adults.

Along with their effects on muscle, omega-3s have also been shown to have a wide range of benefits for cardiometabolic health, most notably via a resolution of inflammation through byproducts of omega-3 metabolism known as specialized pro-resolving mediators or SPMs, but also through their effects on blood lipids and blood pressure, blood clotting, and heart rhythm stabilization.

Exercise does all of these things too, and probably to a greater degree. Which begs the question—do omega-3s and exercise have a health synergy when they're combined? A recent study suggests the answer is yes.

The meta-analysis included 21 studies and 673 participants—most of whom were healthy but some of whom were older adults and individuals who were overweight or obese. A few studies also focused on people with specific conditions such as sarcopenia, hyperlipidemia, or heart failure. 

More than half of the studies used a resistance training intervention, but aerobic training also appeared frequently, either on its own or in combination with resistance training. A few studies used combined training or high-intensity interval training (HIIT). The typical dose of omega-3s ranged between 2 and 3 grams per day, usually consisting of both EPA and DHA. A few studies used lower doses around 1.1 g/day, while the highest reported was 4.5 g/day.

Adding omega-3s to exercise for 8–16 weeks:

• Reduced fat mass by just over 1 kilogram (more than 2.2 pounds).
• Decreased triglycerides (0.1 mmol/L or ~4 mg/dL).
• Lowered the inflammatory biomarker tumor necrosis factor alpha (TNF-alpha).
• Lowered systolic and diastolic blood pressure by ~4 mmHg each.
• Increased lower body strength.

A small increase in LDL was observed—but the change was only around 2.5 mg/dL compared to exercise and unlikely to be clinically relevant.

Final thoughts

These might not seem like impressive changes—and most of them aren't.

But when you consider the fact that this is happening on top of the benefits of exercise, things change. It means that omega-3 supplementation is allowing you to squeeze out a bit more strength, blood pressure improvements, or fat loss from your exercise routine—no extra effort required.

It's a similar analogy to creatine—a foundational supplement that can't replace exercise but can help you get more from exercise.

And like creatine, omega-3s come with several other health benefits that aren't related to exercise—you should be supplementing with them whether you're an elite athlete, a weekend warrior, or even someone who rarely works out.

Here's how to start:

Don't expect results too fast.

Omega-3 supplementation requires a loading phase of several weeks to sufficiently incorporate EPA and DHA into muscle phospholipid membranes—likely a necessary step to fully realize their anabolic and anti-catabolic effects.

For example, in Dr. Chris McGlory’s trial (discussed in episode #81), participants underwent:

• 4 weeks of omega-3 supplementation
• High daily dose (5 grams total: 3 g EPA + 2 g DHA)

They experienced:

• Nearly 50% less muscle loss during two weeks of limb immobilization
• Accelerated muscle mass recovery afterward

Although Chris's trial used a higher initial dose, other research (including the studies highlighted by the meta-analysis above) suggests many muscle and metabolic benefits are also attainable at lower daily doses (2–3 grams). This indicates that after an initial loading period, a lower-dose maintenance phase may be reasonably likely to sustain these effects.

Craving more content on omega-3s and exercise? Check out these timestamps from a few previous FoundMyFitness member Q&As:

Omega-3s:

• Q&A #37 (13:35) - Can omega-3s lower ApoB levels?
• Q&A #39 (7:29) - How omega-3s resolve inflammation via SPMs
• Q&A #39 (10:14) - Is low omega-3 intake as deadly as trans fats?
• Q&A #39 (10:47) - How much omega-3 should you supplement with per day?
• Q&A #53 (1:03:51) - Why Rhonda spaces out her omega-3 intake
• Q&A #56 (11:08) - Are most fish oil supplements oxidized?
• Q&A #56 (12:52) - The TOTOX level to look for when choosing a fish oil supplement
• Q&A #58 (1:10:33) - The low-budget fish oil brand with suprisingly good third-party testing data
• Q&A #60 (01:02) - Does fish oil increase AFib risk?
• Q&A #64 (24:08) - What omega-3 supplement does Rhonda take?

Exercise:

• Q&A #6 (08:49) - The best type of exercise for increasing brain-derived neurotrophic factor (BDNF)
• Q&A #24 (09:12) - How even a 15-minute Peloton ride is enough to boost short-term memory recall
• Q&A #33 (30:04) - Does berberine inhibit the beneficial effects of exercise
• Q&A #53 (1:09:05) - How to use the 12-minute run test to estimate VO2 max
• Q&A #56 (1:10:40) - How combining creatine with resistance training affects strength & fat-free mass
• Q&A #65 (31:23) - How often does Rhonda do "zone 2" cardio?
• Q&A #65 (50:55) - Rhonda's 3x/week strength training routine — and what exercises she focuses on

With appreciation,

Rhonda and the FMF Team