Effect of eicosapentaenoic acids-rich fish oil supplementation on motor nerve function after eccentric contractions

J Int Soc Sports Nutr. 2017 Jul 12:14:23. doi: 10.1186/s12970-017-0176-9. eCollection 2017.


Background: This study investigated the effect of supplementation with fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the M-wave latency of biceps brachii and muscle damage after a single session of maximal elbow flexor eccentric contractions (ECC).

Methods: Twenty-one men were completed the randomized, double-blind, placebo-controlled, and parallel-design study. The subjects were randomly assigned to the fish oil group (n = 10) or control group (n = 11). The fish oil group consumed eight 300-mg EPA-rich fish oil softgel capsules (containing, in total, 600 mg EPA and 260 mg DHA) per day for 8 weeks before the exercise, and continued this for a further 5 days. The control group consumed an equivalent number of placebo capsules. The subjects performed six sets of ten eccentric contractions of the elbow flexors using a dumbbell set at 40% of their one repetition maximum. M-wave latency was assessed as the time taken from electrical stimulation applied to Erb's point to the onset of M-wave of the biceps brachii. This was measured before and immediately after exercise, and then after 1, 2, 3, and 5 days. Changes in maximal voluntary isometric contraction (MVC) torque, range of motion (ROM), upper arm circumference, and delayed onset muscle soreness (DOMS) were assessed at the same time points.

Results: Compared with the control group, M-wave latency was significantly shorter in the fish oil group immediately after exercise (p = 0.040), MVC torque was significantly higher at 1 day after exercise (p = 0.049), ROM was significantly greater at post and 2 days after exercise (post; p = 0.006, day 2; p = 0.014), and there was significantly less delayed onset muscle soreness at 1 and 2 days after exercise (day 1; p = 0.049, day 2; p = 0.023).

Conclusion: Eight weeks of EPA and DHA supplementation may play a protective role against motor nerve function and may attenuate muscle damage after eccentric contractions.

Trial registration: This trial was registered on July 14th 2015 (https://upload.umin.ac.jp/cgi-open-bin/ctr/index.cgi).

Keywords: Eicosapentaenoic acid; Lengthening contractions; M-wave; Muscle damage; Nerve damage; Supplement.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Arm
  • Dietary Supplements
  • Docosahexaenoic Acids / administration & dosage
  • Double-Blind Method
  • Eicosapentaenoic Acid / administration & dosage*
  • Elbow Joint
  • Fish Oils / administration & dosage*
  • Humans
  • Isometric Contraction*
  • Male
  • Motor Neurons / cytology
  • Motor Neurons / drug effects*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / innervation*
  • Myalgia / prevention & control
  • Range of Motion, Articular
  • Torque
  • Young Adult


  • Fish Oils
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid