Dark chocolate, already acknowledged as a health food for its positive effects on heart health, may be the tasty treat that could give athletes an edge in training and competition, according to a study from London’s Kingston University. In fact, the effects may be comparable to beetroot juice, currently used by elite athletes for performance enhancement.
“Beetroot juice contains nitrates the body uses to make nitric oxide, which opens up blood vessels and reduces oxygen consumption, allowing athletes to go further for longer,” explained postgraduate research student Rishikesh Kankesh Patel who conducted the dark chocolate study.
Although not a source of nitrate, dark chocolate provides epicatechins; these members of the flavanol family, cacao being a noted source, enhance nitric oxide production in the body.
Tested A Fortnight
Nine amateur cyclists participated in the study and were split into two groups, one given 40 grams of dark, and the other white, chocolate for a fortnight as snacks.
Heart rate and oxygen consumption were measured during moderate exercise and in time trials. After a seven-day interval, the groups then switched chocolate types and the two-week trial and subsequent exercise tests were repeated.
The study, published in the Journal of the International Society of Sports Nutrition, found that after eating dark chocolate the riders used less oxygen when cycling at a moderate pace and also covered more distance in a 2-minute flat-out time trial.
“Both dark chocolate and beetroot juice are known to increase nitric oxide, which is the major mechanism we believe is behind these results,” Mr Patel said. “We found that people could effectively exercise for longer after eating dark chocolate, something that’s not been established before in this way. We want to see whether the boost in performance is a short term effect—you eat a bar and within a day it works—or whether it takes slightly longer, which is what the initial research is showing,” Mr Patel said.
Beetroot Juice/Chocolate Combo
“We are also investigating the optimal level of flavanols,” he adds. “At the moment there is not a lot of consistency in flavanol levels in commercially available chocolate. Once we’ve found the optimal chocolate dose and duration, we’ll compare its effects to those of beetroot juice and also test the influence of combining consumption of both, as they produce an increase in nitric oxide in slightly different ways.”References
Rishikesh Kankesh Patel, James Brouner, Owen Spendiff. Dark chocolate supplementation reduces the oxygen cost of moderate intensity cycling. Journal of the International Society of Sports Nutrition, 2015; 12 (1) DOI: 10.1186/s12970-015-0106-7