Quercetin boosts performance, recovery in triathletes.
Intense exercise creates oxidative stress, delaying muscle recovery and increasing pain after exercise.
In this study, 48 amateur triathletes, aged 30 to 40, took no supplement or 250 mg of quercetin twice per day for two weeks. All went through the same training including a 750 meter swim in open seawater, cycling 29 kilometers, and running 5 kilometers.
On day one, and again after two weeks, participants completed a baseline run. Runners in the quercetin group beat their original time by 11.3 percent compared to a 3.9 percent improvement for the non-supplement group. Afterwards, the quercetin group reported less post-run muscle pain, fewer cramps, less localized pain, and faster recovery times. (Reference: Minerva Medica; 2018, Vol. 109, No. 4, 285-9)
Quercetin is a flavonoid that occurs in foods such as onions, apples, berries, teas, and red wine. It is also found in several herbs including Ginkgo biloba, St. John's wort, and American elder (Sambucus canadensis).
Besides sports, what is quercetin typically used for? Orally, quercetin is used for atherosclerosis, hypercholesterolemia, hypertension, coronary heart disease, vascular insufficiency, diabetes, cataracts, allergic rhinitis, peptic ulcers, aphthous ulcers, schizophrenia, inflammation, rheumatoid arthritis (RA), niacin flush, asthma, gout, viral infections, bladder disorders and infections, chronic fatigue syndrome (CFS), preventing cancer, oral mucositis, treating prostatitis, improving hormone levels in women with polycystic ovary syndrome, and improving function of kidney transplants.
As already pointed out, It is also used to increase exercise endurance and improve athletic performance. Here is another recent study that supports this use.
Quercetin protects muscles. Earlier exercise studies using antioxidants have had inconsistent muscle-damage results. In this study, 12 moderately active men, average age 26, took a placebo or 500 mg of quercetin at breakfast and again 12 hours later over two weeks. After a three week non-treatment period, the men switched groups.
Putting muscles under load while lengthening them is the fastest way to induce damage. At the start and end of the study, the men did 10 sets of 10 maximal muscle-lengthening contractions. While the placebo group had not changed, men taking quercetin saw a 4.7 percent increase in isometric strength, and muscle fiber decay was significantly lower.
Doctors also saw fewer biochemical signs of damage, and observed better muscle function, commenting that quercetin seems to be a suitable nutritional supplement to reduce discomfort, maintain strength, and may improve overall fitness. (Reference: Nutrients; 2019, Vol. 11, No. 1, 205)