Poster Topical Area: Sports Nutrition
Poster Board Number: 248
Objective: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seems to be enhancement of exercise performance. With regard to the effects of EPA and DHA on whole-body endurance performance, previous studies show that long-term (6–8 weeks) EPA and DHA supplementation increased maximal oxygen uptake. However, no study investigated the effect of EPA and DHA supplementation on peripheral muscle performance in humans. The aim of this study was to test the hypothesis that 8-week fish oil (EPA and DHA) supplementation improves peripheral muscle performance by concentric contractions (CONs) of elbow flexors in humans.
Methods: Sixteen healthy men were randomly administered with fish oil supplement (FO, n = 8) or placebo (PL, n = 8) by a double-blind method. The FO group ingested eight 300 mg EPA-rich fish oil softgel capsules per day, amounting to 2,400 mg per day, containing 600 mg EPA and 260 mg DHA for 8 weeks. The CONs consisted of five sets of six maximal voluntary isokinetic (30°/s) CONs of the elbow flexors with range of motion (ROM) from 0° (full extension) to 90°. The work output and peak torque were assessed during exercise. Changes in the maximal voluntary isometric contraction (MVC) torque, ROM, upper arm circumference, muscle fatigue by rating of perceived exertion (RPE), transverse relaxation time (T2), cross-sectional area (CSA), and lactate, derivatives of reactive oxygen metabolites (d-ROM), and biological antioxidant potential (BAP) in blood were also assessed before, immediately after, and 1 day after exercise.
Results: The work output during CONs in the FO group was greater than that in the placebo group at the fifth set (p < 0.05). In addition, ROM in the FO group was significantly greater than that in the PL group immediately after exercise (p < 0.05). The increase of CSA in the FO group was significantly smaller than that in the PL group immediately after exercise (p < 0.05). However, no significant difference between FO group and PL group was found for MVC torque, upper arm circumference, RPE, T2, lactate, d-ROM, and BAP.
Conclusions: The present study suggests that the reduction of muscle work output caused by 30 CONs can be attenuated by an 8-week fish oil supplementation. In addition, fish oil supplementation may prevent for reduction of ROM and increase of CSA after CONs.
This study was funded by Nippon Suisan Kaisha,Ltd.
Koganei, Tokyo, Japan