Dark Chocolate Boosts Oxygen Consumption
Dark chocolate is high in flavonoids, which promote blood flow. Rishikesh Patel from Kingston University in the U.K., and co-workers, found that consuming 30 grams of dark chocolate per day for 14 days caused slight increases in maximal oxygen consumption, cycling efficiency and gas exchange threshold— the point at which expired carbon dioxide increases abruptly. These effects were small, and might not make much difference in performance. Many recent studies have touted the beneficial effects of flavonoids and polyphenol in food such as chocolate and red wine. They are somewhat effective in reducing inflammation and free radical damage to cells. They may have long-term health benefits, but probably have few meaningful acute effects on exercise performance.
(Journal International Society Sports Nutrition, 12: 47, 2015)