Athletes use nutrition strategies to improve training through increasing metabolic capacity, delaying muscle fatigue, and improving muscle hypertrophy. As a bodybuilder, your training, nutrition, and supplement regimen can become quite rigorous and cumbersome.

Fish oil is often one of the supplements suggested by bodybuilding coaches for several reasons, mainly the anti-inflammatory properties, and the valuable benefits that come along with omega-3 essential fatty acids, like joint, brain, and heart health. 

We’re going to dig into the benefits of fish oil for bodybuilding and why you should be taking an omega-3 supplement when you’re prepping to get on stage.

What Is Fish Oil? Benefits for Bodybuilders, Athletes, and Everyday Performance

Fish oil is a popular dietary supplement extracted from fatty fish such as salmon, mackerel, herring, and halibut. Rich in omega-3 essential fatty acids—specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—fish oil provides a wide range of clinically supported health benefits, particularly for heart health, brain function, joint support, and athletic performance.

Why Omega-3 Fatty Acids Matter

Omega-3s are classified as essential fatty acids, meaning they cannot be synthesized by the body and must be consumed through food or supplementation Calder, 2015, Nutrients. For athletes and bodybuilders—especially those in a cutting phase (6–8 weeks out from competition)—dietary fat intake is often drastically reduced. During this time, incorporating omega-3 supplements like fish oil becomes critical to offset potential deficiencies.

RELATED ARTICLE: Bodybuilding Cutting Diet

Fish Oil Benefits for Bodybuilders

Before diving into the specific benefits, it’s important to note: the value of fish oil comes from EPA and DHA—not the oil itself. Other omega-3 sources include krill oil, cod liver oil, and flaxseed oil. Among them, krill oil stands out as a superior option due to its enhanced absorption and natural antioxidant content Ulven & Holven, 2015, Frontiers in Nutrition.

In fact, research shows that krill oil is absorbed 68% better than fish oil, becoming bioavailable in 2–3 hours, while fish oil may take 48–72 hours Maki et al., 2009, Journal of the American College of Nutrition.

1. Improves Athletic Performance

Emerging evidence supports the use of omega-3 fatty acids as ergogenic aids—enhancing training, performance, and recovery.

Key Findings:

• Astaxanthin, a powerful antioxidant naturally found in krill oil, has been shown to:

  • Reduce exercise-induced muscle damage

  • Improve peak power output

  • Enhance strength and endurance capacity
    Earnest et al., 2011, International Journal of Sports Medicine

• Omega-3 supplementation may also:

  • Increase peak torque and muscle strength

  • Improve VO2 max (maximal oxygen uptake)

  • Reduce muscle fatigue and soreness
    Lewis et al., 2015, Journal of the International Society of Sports Nutrition
    Grimble, 2007, British Journal of Nutrition

Several studies suggest that even 500mg of omega-3 daily can lead to significant improvements in training output, muscle recovery, and inflammation reduction.

RELATED ARTICLE: The Ultimate Guide to Krill Oil

Fish Oil for Bodybuilding: Body Composition, Recovery, and Joint Health

Fish oil and omega-3 fatty acids are increasingly recognized for their ability to support not only overall health but also bodybuilding-specific goals like muscle growth, fat reduction, recovery, and joint support. Here's how they contribute to performance—especially when paired with intense training and cutting phases.

2. May Improve Body Composition

Cutting body fat is a critical part of prepping for the stage. Research has shown that omega-3s can support favorable body composition by helping to increase lean muscle mass and reduce body fat.

A study published in the Journal of the International Society of Sports Nutrition examined the effects of fish oil on resting metabolic rate (RMR) and body composition. Forty-four men consumed either 4g of safflower oil or 4g of fish oil daily for six weeks. Those in the fish oil group experienced significant gains in lean mass and reductions in fat mass
Logan & Spriet, 2010, JISSN.

Additionally, a study by the Department of Comparative Biosciences at the University of Wisconsin–Madison looked at krill oil’s effect on mTOR signaling, a pathway that regulates protein synthesis and muscle hypertrophy
Kimball & Jefferson, 2006, Annual Review of Nutrition.

An 8-week study published in Nutrition & Metabolism found that krill oil supplementation, combined with resistance training, significantly increased both lean body mass and strength
Kalman et al., 2020, Nutrition & Metabolism.

3. May Reduce Muscle Soreness and Improve Recovery

Recovery is a cornerstone of muscle growth and performance. One of fish oil’s most notable benefits lies in its ability to reduce delayed onset muscle soreness (DOMS) and support faster recovery by lowering muscle damage and inflammation.

DOMS, typically caused by microtrauma to muscle fibers, can lead to soreness, reduced range of motion, and decreased strength. Studies show that EPA and DHA:

• Reduce inflammation post-exercise

• Minimize muscle strength loss

• Enhance muscle recovery
  Jouris et al., 2011, Clinical Journal of Sport Medicine

Krill oil, which contains astaxanthin, goes a step further. This potent antioxidant has been shown to:

• Decrease oxidative stress

• Protect the immune system post-exercise

• Further limit muscle damage compared to fish oil
  Fassett & Coombes, 2011, Marine Drugs

4. Improves Joint Health

Intense training and the use of performance-enhancing compounds can put considerable stress on the joints. Chronic inflammation in joints and tendons can reduce quality of life and limit training output.

Omega-3 fatty acids are known for their anti-inflammatory effects, particularly in reducing joint stiffness and pain. In a randomized, double-blind, placebo-controlled trial published in the Journal of the American College of Nutrition, 90 participants with rheumatoid or osteoarthritis were given 300mg of krill oil daily.

After just seven days, participants experienced:

• 28.9% reduction in pain

• 20.3% reduction in stiffness

• 22.8% reduction in functional impairment
  Deutsch, 2007, JACN

This is particularly helpful for bodybuilders experiencing joint pain during high-volume training or prep.

Recommended Dose of Fish Oil for Bodybuilders

Depending on your training intensity and nutritional needs, here’s a breakdown of effective dosing:

• For muscle recovery:

  • Fish Oil: 3–6g/day

  • Krill Oil: 1–3g/day (more bioavailable)
    Lewis et al., 2015, JISSN

• For muscle growth and mTOR activation:

  • 2–3g/day is effective

  • 5g/day may serve as a safe upper limit

While direct research on fish oil and hypertrophy is still emerging, supplementing with omega-3s remains a strong strategy—especially if your diet is low in healthy fats or cold-water fish sources.

Fish Oil for Bodybuilders: Takeaway

Fish oil offers a variety of science-backed benefits for bodybuilders, including:

• Reduced muscle soreness

• Increased strength

• Improved body composition

• Enhanced peak power output

These effects are primarily attributed to the essential omega-3 fatty acids EPA and DHA, which play a critical role in reducing inflammation, enhancing recovery, and supporting performance.

While traditional fish oil is beneficial, krill oil has been shown to be a superior form of omega-3, offering enhanced bioavailability and the added benefit of astaxanthin—a potent antioxidant that helps combat oxidative stress and the body’s inflammatory response.

With krill oil requiring only half the dose of traditional fish oil to deliver similar (or greater) benefits, it presents a compelling alternative for those seeking maximum results from their supplementation.

Regardless of which omega-3 source you choose, incorporating a high-quality omega-3 supplement into your regimen is a smart strategy for bodybuilders looking to optimize their recovery, strength, and training longevity.