Journal Title (Medline/Pubmed accepted abbreviation): J Sports Sci Med
Page number: 432-438
doi (if applicable):
Summary of background and research design:
Background: Although the anti-inflammatory properties of omega-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) have been extensively studied in various diseases and conditions, few studies have evaluated the effects on exercise-induced inflammation.
Hypothesis/Purpose: Omega-3 supplementation will attenuate the increases in subjective measures of exercise-indued inflammation (soreness, swelling, and skin temperature).
Subjects: Eleven healthy adults (8 women and 3 men) participated in this study (respective mean ages, 34.1 and 37.0 y; height, 1.6 and 1.8 m; weight, 59.8 and 78.2 kg; body mass index, 22.1 and 23.5 kg/m2).
Experimental design: Intervention, cross-over
Treatments Protocol: The adults performed an eccentric exercise (unilateral bicep curls) following a 14-day control diet (omega-3 restricted) and then the same eccentric exercise following a 7-day omega-3 supplemented diet (2,000 mg EPA and 1,000 mg DHA per day). The eccentric exercise consisted of 2 sets of bicep curls (lowering over 4 sec until exhaustion) at 120% of 1-maximum repetition (determined before testing), with a 60-second rest between sets. Pairing of diet condition was stratified by arm dominance; half of the adults were tested with dominant arm during control and non-dominant arm during omega-3 supplementation and vice versa for the other half of adults. Arm circumference (swelling), skin temperature, and muscle soreness were assessed before exercise and 48 hours after exercise.
Summary of research findings:
- The omega-3 group completed more repetitions in each set despite no difference in weight used and, therefore, a greater total exercise volume compared with the control group.
- Set 1 repetitions: 21 vs 18, respectively, P = .05; set 2 repetitions: 10 vs 8, respectively, P = .02.
- Exercise volume: 321 vs 280 kg*rep, respectively, P = .01.
- The omega-3 group had less muscle soreness when weighted or fully extended compared with the control group (P ≤ .02 for both).
- No difference in muscle soreness was observed between groups when palpated.
- Arm circumference increased significantly from baseline in the control group (P = .01) and not in the omega-3 group (P = .15); however, there was no difference between groups (P = .45).
- No significant differences were observed in skin temperature between the 2 conditions.
Interpretation of findings/Key practice applications:
In this study, omega-3 supplementation decreased muscle soreness after high-intensity exercise. Results were observed after only 7 days of supplementation, suggesting that chronic usage is not required for an effect. Although the majority of adults had trouble completing a full elbow extension 48 hours after the exercise, arm circumference did not significantly change between the groups. Therefore, arm circumference may not be a sensitive test for inflammation. This study was limited by the small size and lack of a placebo pill as part of the control treatment.