EPA and DHA help distance runners avoid muscle damage in sports nutrition study

Omega-3s were shown to ameliorate the muscle damage that comes from downhill running in a study that adds, in a small way, to the growing body of sports nutrition evidence for EPA and DHA. 

The new research in sports nutrition was published in the Journal of Human Kinetics. The research that used omega-3s as an intervention was the work of a team associated with two institutes in Katowice, Poland. 

Research accumulating for effects of omega-3s in sports nutrition 

The researchers noted past science in the sports nutrition sector has associated omega-3s with reduced muscle damage and other important parameters. This study adds to that story, which is an up-and-coming research area, according to noted omega-3s researcher Dr. William Harris, Ph.D., head of the Fatty Acid Research Institute. 

The researchers designed a placebo-controlled, blinded study to test the ability of a high-dose fish oil supplement to benefit distance runners. 

For a test material, the researchers turned to a Polish manufacturer to provide a highly refined fish oil omega-3 supplement that supplied 450 milligrams (142 mg of EPA and 267 mg of DHA) of omega-3s in each 500-mg capsule. The subjects in the intervention group took six such capsules a day for a total dose of 3000 mg of omega-3s, while the other group took an equivalent placebo. 

Related:NIH: Omega-3 Supplements Largely Meet Label Claims

Cohort of distance runners 

For test subjects, the researchers recruited a cohort of 24 trained male distance runners who were in their mid-30s.  

The subjects were tested in the lab at three different intervals. One session consisted of a standard aerobic test to exhaustion on a treadmill to determine individual fitness parameters. 

The other two intervals were 30-minute downhill runs on a treadmill set to a 16-degree downgrade with the speed set to match each runner’s 70% VO2max level. The researchers said this has become a standard protocol for inducing exercise-related muscle damage. 

The first downhill running session took place before supplementation, with the second set for the end of three weeks of taking the six fish oil or placebo capsules per day. The participants were asked to continue their standard training regimens and adhere to a standard diet during that three-week period. 

Markers of muscle damage were assessed by analyzing blood samples taken from the subjects at various intervals during the research. The researchers also performed electrocardiograms and took blood pressure readings as well as measuring the contents of the subjects’ breath. 

In addition, the researchers evaluated the change in the subjects’ omega-3 index, which measures how much EPA and DPA is in a person’s red blood cells. Typical values for this measure in Western populations are about 3% to 5%. Health authorities recommend that people aim to raise this to 8% to get the best cardiovascular protection. 

The Polish researchers said the 8% level was not achieved during their study (probably because the study period was too short), but the omega-3s supplementation did reduce markers of muscle damage, such as cutting the expression of pro-inflammatory cytokines. 

“The increased erythrocyte membrane EPA and DHA content and lower blood concentrations of the cardiac damage markers and inflammation mediators measured after downhill running in distance runners supplemented for three weeks with ω 3 PUFA suggest that their cardiovascular function and regeneration capacity after the eccentric muscle-damaging exercise protocols were improved,” the researchers concluded. 

Study was short, but complicated 

Harris noted trying to find a significant change in the omega-3 index in so short a time might have been misguided, but the other results are in line with other research in this area. He said the large number of outcomes the researchers were trying to measure could be seen as a confounding factor. 

“Their findings should have been adjusted for ‘multiple testing’ since there were so many outcomes that they measured. But the direction seems pretty clear,” Harris noted. “Always taking these small and short studies with a grain of salt makes sense, but this is encouraging.”