• The effect of flavonid supplementation in alleviating the symptoms of eccentric exercise induced muscle damage in humans: a systematic review

      Hansson, Josefine (University of Chester, 2016-09)
      Background: Eccentric exercise can cause damage to skeletal-muscle fibres, which can lead to loss of strength, swelling, delayed onset muscle soreness (DOMS), and increased blood levels of muscle damage markers. Antioxidant supplements containing flavonoids are used by many athletes and recreationally active individuals hoping to counteract the damage produced by eccentric exercise. The objective of this study was to evaluate the evidence for flavonoid supplementation on the symptoms associated EEIMD. Methods: Four electronic database literature searches were conducted (PubMed, Sport Discus, Science Direct, and Wiley Online Library) to identify studies investigating the effect of flavonoid supplementation on symptoms associated with EEIMD. Randomised controlled trials that utilised supplementation of flavonoids on human subjects exhibiting EEIMD were included. The Jadad scale were used to assess the quality of the studies. Results: Six studies were identified that fulfilled the selection criteria. All studies were randomised, whereas four were double blinded. One study demonstrated reduced muscle strength-loss and pain after supplementing with cherry, and one study found that blueberry supplementation enhanced muscle speed recovery. Black currant supplementation reduced circulating markers of muscle damage but had no effect on pain. Three studies were unable to demonstrate any significant effect of flavonoid supplementation (fruit/berry/vegetable supplement, quercetin, and grape) on recovery from eccentric exercise. Conclusion: For any particular flavonoid studied within an eccentric exercise context, few papers are available, and there is a variation with regard to the supplementation dose and regimen, the mode of exercise as well as outcome measures. However, in the majority of the well- designed, bias-controlled studies compared to placebo receiving subjects’ flavonoid supplementation were unable to influence symptoms associated with EEIMD.