Antioxidants have been commonly used to protect against damage secondary to exercise; however, there have been mixed results. In addition, there has been some debate that using high doses of antioxidants, such as vitamin C and E, may counteract the upregulation of endogenous antioxidant defenses that are naturally triggered as a response to exercise.

Quercetin, a polyphenol, has been shown to have both strong antioxidant and anti-inflammatory properties. Recently, quercetin has received a lot of attention for its strong immune properties. It is one of the ubiquitous flavonoids found in many Chinese herbs, fruits, and vegetables. Common foods include blueberries, red onions, broccoli, cauliflower, kale, and many nuts. Research has demonstrated that quercetin supplementation has antihypertensive, anticoagulant, and antihyperglycemic properties.

 According to a study published last week in Nutrients, researchers investigated if quercetin supplementation can improve the recovery of neuromuscular function. This was a double-blinded, placebo-controlled, crossover study that included 16 men who were randomized to take 1,000 mg of quercetin a day or a placebo and then cross over to the opposite treatment after a 3-week washout period. All the participants avoided foods containing quercetin for the duration of the study.

 A neuromuscular evaluation was performed assessing muscle damage at baseline, at 24 hours, at 48 hours, at 72 hours, at 96 hours, and at 7 days after intense eccentric exercise. The force–velocity relationship and maximal voluntary isometric contraction were recorded by electromyography. Other assessments included pain, joint angle, arm circumference, creatine kinase, and lactate dehydrogenase.

 As a result, quercetin supplementation significantly mitigated strength loss compared to a placebo. In addition, biomarkers and functional indications of muscular damage were significantly less in the quercetin group. This study demonstrates that quercetin supplementation can improve the recovery of eccentric exercise-induced weakness, neuromuscular function, and biochemical parameters due to its strong anti-inflammatory and antioxidant properties. Other nutrients to consider include whey protein, astaxanthin, and fish oil.

 Astaxanthin is a red-orange carotenoid, which is mainly produced by micro-algae (Haematococcus pluvialis), and it accumulates in many marine organisms, such as salmon, trout, shrimp, and lobster. The unique molecular structure of astaxanthin provides its distinctive features such as higher antioxidant activity than other carotenoids. Previous research suggests that astaxanthin protects against exercise-induced fatigue, as it decreases oxidative stress and the inflammatory response. 

By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS

Source: Bazzucchi I, Patrizio F, Ceci R, et al. Quercetin Supplementation Improves Neuromuscular Function Recovery from Muscle Damage. Nutrients 2020;12(9):2850. doi.org/10.3390/nu12092850.