Why omega-3s may be vital to getting the most out of your daily workouts

Most people know omega-3 fish oils are good for health – especially heart health. But what many people might not realise is that these friendly fats can also be beneficial to your workouts.

Research has linked omega-3s to better exercise performance – making them a potentially valuable supplement for people who train regularly.

Omega-3 fatty acids are special fats found mainly in fish, seafood, nuts and seeds (such as walnuts and flaxseed), as well as some plant oils.

The main forms of omega-3s are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are essential for the structure and function of cells, especially in the muscles, heart and brain. This is because they help with “membrane fluidity” – the flow of nutrients or chemicals into cells.

To ensure adequate omega-3 levels, people need to get them from their diet. Although there’s no universal agreement on how much to eat, most health bodies recommend 1.4-2.5g a day of omega‑3 – with 140-600mg per day coming specifically from EPA and DHA. Around 500mg daily of EPA and DHA combined is enough to support health and benefit exercise.

Omega-3s and exercise

Exercise – especially resistance training (such as lifting weights) and hard-training sessions (such as cross-fit) – places stress on the muscles, causing small amounts of damage that triggers inflammation as part of the body’s repair process. Some inflammation is necessary for adaptation, but too much or prolonged inflammation may delay recovery and reduce performance.

Omega-3s have been found to act like “traffic controllers,” helping regulate the body’s inflammatory response to exercise so muscles recover more efficiently.

EPA also appears to support better blood flow to muscles after training and enhances the process of muscle protein synthesis (the body’s way of building new muscle tissue). Both of these processes may improve recovery following repeated sessions.

Research in physically active adults has even shown that taking fish oil containing EPA and DHA for several weeks enhanced muscle strength gains in resistance exercise performance compared to those who did the same type of training but did not take an omega-3 supplement.

EPA and DHA therefore appear to help the body recover and adapt to training more effectively over time.

DHA is important for the brain and nervous system, supporting cognitive function and nerve signals that help muscle to work efficiently while exercising. People who exercise regularly and take an omega-3 supplement also have higher DHA levels in their muscle cell membranes compared to those who are sedentary. This could be key for recovery and adaptation from exercise.

Omega-3 balance

Although omega-3 can be obtained from the diet, the amount of EPA and DHA in food can vary depending on the type of fish, whether it’s wild or farmed, what these farmed fish are fed and how the food is stored or cooked.

Modern diets also often provide far more omega-6 than omega-3, which may promote inflammation. This is because omega-6 fats produce pro-inflammatory compounds, whereas omega-3s produce anti-inflammatory ones. This balance can be improved by increasing omega-3s, reducing consumption of processed foods and omega-6-rich oils (such as corn, safflower and soybean oils).

To support a healthy omega‑3 status, include a variety of fatty fish, seafood and plant sources such as chia or linseed. Also aim to choose low glycaemic carbohydrates such as oats, legumes and most fruits. This is because low glycaemic foods release sugar slowly into the blood, which helps your body use fats as fuel more effectively.

High-glycaemic foods on the other hand, such as white bread, sugary drinks or refined grains, release sugar quickly. This can reduce how well omega-3s are incorporated into cells and may increase inflammation.

Most people can get enough omega-3 from a healthy diet that contains oily fish, but supplements can be a practical option if these foods aren’t eaten or if higher intakes are needed. While fish oil supplements can be a beneficial strategy to boost your omega-3 levels, to see measurable changes in muscles and overall health, daily intake for at least two weeks is recommended.

For most active people, this means 3-5g of fish oil per day, ideally with a high concentration of EPA and DHA. Omega-3s are best absorbed when taken with meals containing some fat. Therefore, splitting the dose (such as taking some with breakfast and dinner) improves absorption and tolerance.

For muscle growth and functional performance, a supplement providing around 1.8g of EPA and 1.5g of DHA per day is suggested. This is roughly equivalent to the omega-3 content found in 200–400g of fatty fish such as salmon, herring or sardines.

If your goal is to support brain health, cognitive function or mood, a higher proportion of DHA may be beneficial. So instead of getting a supplement containing an equal 1:1 ratio of EPA and DHA, aim to purchase a supplement containing a 1:8 ratio of EPA to DHA (such as 100mg EPA and 800mg DHA). Typical products vary widely, so readers should check the EPA and DHA content rather than the total fish oil amount.

Omega-3 supplements are generally safe, but some people may experience a mild, fishy aftertaste or upset stomach after taking one – particularly when taking higher doses or when taken without food. Intakes above 5g per day of EPA+DHA from supplements should be avoided, unless medically advised.

Omega-3s may help support both health, recovery and adaptation to training, and indeed may be an important nutritional component for those who exercise regularly. While a balanced diet should come first, omega-3 supplements can be helpful in keeping up with training demands when diet is insufficient.

Professor F Naclerio has previously received external research funding unrelated to this article.

Professor Roberts has previously received external research funding unrelated to this article.