Quercetin (from Sophora Japonica Seed Extract)
Quercetin is mostly found in fruits and vegetables. Quercetin dihydrate when taken with green tea has shown benefits in increasing the absorption of green tea. Other benefits include being able to activate the brain along the lines of caffeine but to a smaller degree. Another benefit of quercetin is that it is an antioxidant.(72)
Oxygen utilization is increased during exercising by 10 to 20 times over the resting state. Free radical production is greatly increased because of this.(17) Antioxidants are molecules that can scavenge free radicals and get rid of them before vital molecules are damaged.(18) Antioxidant properties can have a positive effect on endurance.
Quercetin is considered a polyphenol which is an antioxidant.(73) In a human diet polyphenols are actually the most abundant antioxidant.(73) Polyphenol benefits include muscle strength, muscle size and fat loss.(75)
Quercetin helps to block an enzyme in the liver known as (UGT2B17). This enzyme tells the kidney to urinate testosterone out of the body. By quercetin blocking (UGT2B17) it can allow testosterone to stay in the body longer.(74)