The effectiveness of fish oil supplementation in attenuating eccentric exercise-induced muscle damage in females during mid-follicular and mid-luteal menstrual phases
Access changed 12/15/21.
Due to the supposed cyto-protective effects of estrogen, females are thought to be less predisposed to EIMD than males, but may be more prone to muscle damage during the low estrogen point in their 28-day cycle (follicular phase) compared to their high estrogen point (luteal phase). Fish oil supplementation has been suggested to be important for cyto-protection due to its anti-oxidant potential for significantly decreasing markers of muscle damage. In a double-blind fashion 22 physically-active females were randomly assigned to ingest either 6 grams of fish oil (n = 11) or a placebo (n = 11) daily for 21 days. Participants underwent an eccentric exercise bout of the knee extensors on two occasions, during the mid-luteal phase (day 21) and mid-follicular phase (day 6) of the 28-day menstrual cycle. Prior to, at 6, and 24 hours post-exercise for each session, participants underwent assessment of DOMS, muscle strength, and had venous blood samples and muscle biopsies obtained. Criterion variables included serum markers of muscle damage, inflammation, and oxidative stress (SOD, myoglobin, TNF-α), skeletal muscle markers of NF-κB signaling, DOMS, and muscle strength. Data was analyzed utilizing a 2 x 2 x 3 repeated measures MANOVA. Further analysis of the main effects for Test was performed by a separate one-way ANOVA. Significant between-group differences were then determined involving the Tukey LSD Post Hoc Test. The alpha level for statistical significance was set at p ≤ .05. DOMS was significantly greater at the 6HRPOST and 24HRPOST time points compared to PRE (p ≤ .05). SOD concentrations were significantly higher at the MF phase compared to the ML phase (p ≤ .05). TNF-α concentrations were significantly higher in the experimental group compared to the placebo group (p < .05), and at the MF phase compared to the ML phase (p < .05). There were no significant differences observed for muscle strength, myoglobin, NF-KB p50 or p65. The results of this study demonstrate that estrogen, but not fish oil supplementation, may exert a cyto-protective effect on the sarcolemma.