The Potential Cytoprotective Influence of Estradiol and Fish Oil Supplementation on Indices of Exercise-Induced Muscle Damage in Females

Abstract

Exercise-induced muscle damage (EIMD) occurs following unaccustomed exercise, usually involving eccentric muscle contractions. Eccentric exercise contractions may cause harsh morphological changes in the individual muscle fiber. Various interventions have been proposed to attenuate EIMD and delayed onset muscle soreness (DOMS). An intriguing proposed intervention involves 17-? estradiol (estrogen) as an anti-oxidant. Estrogen has a cyto-protective effect on the sarcolemma, which protects the muscle from oxidative-induced muscle damage known to occur with strenuous exercise. It has been theorized that estrogen has the functional capacity to act as a membrane stabilizer, Due to the supposed cytoprotective effects of estrogen, females are thought to be less predisposed to exercise-induced muscle damage than males. However, females may be more prone to muscle damage during the low estrogen point in their 28-35 day cycle (follicular phase) compared to their high estrogen point (luteal phase). Numerous treatments have been proposed to minimize muscle damage and alleviate the symptoms of DOMS, but a clear beneficial treatment has not yet been identified. Another intriguing idea is that the anti-inflammatory and anti-oxidative properties of omega-3 (n-3) fatty acids may help counteract the inflammatory state associated with muscle damage and DOMS. The omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are of interest as they are common components of fish oil supplements and have been shown to be beneficial in improving some inflammatory conditions. As a result, fish oil supplementation has been suggested to be important for cytoprotection due to its anti-oxidant potential for significantly decreasing markers of muscle damage. Therefore, fish oil supplementation may reduce oxidative stress, thereby augmenting cytoprotection throughout the course of the 28-day menstrual cycle.