Omega-3 fatty acids offer a cornucopia of health benefits, including anti-inflammatory properties, improvements in joint pain, better brain health, and improved cardiac function. Still, 98% of all Americans fall short of meeting the RDA of Omega-3 intake. Supplementing with krill oil, a rich source of polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can greatly improve not only general health but also post-exercise immune function, muscular strength, and athletic performance.

Fish Oil versus Krill Oil

Krill oil, derived from tiny shrimp-like crustaceans found deep in the frigid waters of the Antarctic Ocean, figures prominently in the diet of the wildlife that inhabit that region: whales, penguins, and other sea creatures. On a number of facets, krill oil varies greatly from more ubiquitous fish oil, impacting the way our bodies utilize it.

The bioavailability/absorption rate of krill oil, owing to its unique molecular structure, explains part of the reason scientists and dietitians deem it a preferable source for the body over traditional fish oil. Essential fatty acids from fish oil come packaged as triglycerides, whereas krill oil delivers phospholipids; these mimic the structure of cellular membranes, enabling the body to utilize them immediately upon ingestion.

As a result, krill oil increases blood plasma levels of EPA and DHA at a 68% faster rate than fish oil. All of this means an athlete can experience more effective post-exercise recovery. The potent antioxidant astaxanthin occurs naturally in krill oil. This substance offers significant anti-inflammatory properties, which can help in fostering a healthier heart, diminishing muscle damage, and considerably improving muscle recovery.

Athletes and Inflammation

One noteworthy study recruited 19 males and 18 females, all approximately 25-30 years of age, and randomly assigned them to receive either 2 g/day of krill oil or a placebo over the course of six weeks. The physical aspect of the experiment included exercise tests and cycling time trials. Scientists collected blood samples both pre- and post- supplementation, prior to the subjects’ engaging in physical activity, and then again immediately following exercise, at one-hour post-exercise, and at the three-hour post-exercise mark.

Six weeks of krill oil supplementation showed great promise in increasing Interleukin-2 (IL-2) production at the three-hour post-exercise mark in subjects of both genders. IL-2 is one in a family of polypeptides that amplify immune responses in the body. It also stimulates proliferation of/enhances function of natural killer (NK) cells, which in turn promote cell cytotoxic activity. Cytotoxic cells possess the ability to eliminate/kill foreign cells, cancer cells, and virus-riddled cells. They often get referred to as “killer T cells”, due to their immune-system clean-up capabilities.

Scientists have outlined possible different health effects of supplementing with krill oil and fish oil, focusing on inflammatory markers, cardiovascular disease risk, and other physiological functions. A variation in the bioavailability of EPA and DHA also seemed to hold some promise. As this field of interest expands, we shall await the results of more studies before arriving at a definitive conclusion regarding the most optimal Omega-3 supplement.

Krill Oil, mTor, and Muscle Synthesis

Muscle protein synthesis (MPS) refers to the process of building new proteins, specifically those which facilitate hypertrophy. Protein synthesis occurs in response to exercise and resistance training, utilizing amino acids to rebuild and repair muscle mass.

Maintenance of skeletal muscle mass depends entirely upon the balance between the body’s anabolic (building) and catabolic (tearing down) processes. The kinase known as mTOR controls these competing processes, constantly shifting to accommodate an appropriate balance.

A recent study conducted at the University of Wisconsin/Madison’s Department of Comparative Biosciences looked at the manner in which krill oil affects mTOR signaling and resistance training, and its subsequent effect on MPS. The study determined that krill oil exerted a profound effect on muscle protein synthesis as well as increased lean body mass.

Seeking the Best Nutritional Choices

Unlike most fish oil supplements on today’s market, krill oil offers the following benefits ~

  • Contains an abundance of EPA and DHA
  • Facilitates muscle protein synthesis and immunological properties
  • Smaller capsule size makes supplementation easier
  • Eliminates the dreaded and often uncomfortable “fishy burps” experienced with fish oil

If your clients already eat fish on a regular basis (3-4 times each week), they may not seek out additional supplementation. However, for your meat-and-potatoes-only clients, you can now shed some light on the plethora of advantages of “food with fins”.

Even if they do not happen to fancy eating fish, trainers can encourage these clients to experiment with including the following in their weekly meal planning:

  • oysters
  • mackerel
  • seaweed
  • spirulina/algae
  • salmon
  • shrimp
  • trout
  • sardines
  • kidney beans
  • edamame

Many tasty meals and side dishes can easily incorporate the aforementioned foods, which typically appear in most large-chain groceries and specialty food shops. Trainers may even try out some recipes first, and then recommend the highly successful ones to their clientele.


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Cathleen Kronemer

Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at She welcomes your feedback and your comments!