Dark chocolate boosts athletic performance and endurance

Dark chocolate has quickly earned a reputation as a superfood with vast human health benefits. Scientists continue to reveal the vast benefits of dark chocolate, including supporting cardiovascular health, providing powerful antioxidants to combat free radical damage, and enhancing brain function. On April 19, 2016, scientists at London’s Kingston University announced an impressive reason for athletes to also celebrate and eat dark chocolate — eating it enhances athletic performance and endurance.

Dark chocolate (chocolate with 70% or more cacao content) is highly nutritious, providing such valuable nutrients as fiber, fatty acids, iron, magnesium, copper, and manganese. In addition, dark chocolate is loaded with antioxidants like polyphenols, flavanols, and catechins; and combats free radicals better than other superfoods such as acai berries.(1)

Now, the caveat is dark chocolate is also high in calories — a whopping 600 calories per 100 grams — and contains about six teaspoons of sugar in the same serving, so only small amounts should be consumed on a regular basis. A reasonable daily amount to consume may be 30 to 50 g daily, aiming for 85% cacao content.

Evidence demonstrates that dark chocolate relaxes the arteries to allow blood to flow more freely and mildly lowers blood pressure.(2) In addition, dark chocolate favorably affects cholesterol levels—decreasing LDL cholesterol and oxidized cholesterol while simultaneously increasing HDL cholesterol.(3) These two benefits may contribute to an overall decrease in cardiovascular disease risk. Indeed, research suggests eating dark chocolate most days of the week decreases the risk of cardiovascular disease by 57%.(4)

Adding to the mounting body of evidence that dark chocolate is a beneficial superfood, scientists at London’s Kingston University suggest that dark chocolate may give athletes and weekend warriors an edge to achieve their fitness goals. The team of researchers led by Rishikesh Kanesh Patel sought to investigate whether epicatechin — a flavanol found in dark chocolate known to increase nitric oxide production in the body — could enhance athletic performance similarly to beetroot juice.

Beet root juice contains nitrates that the body converts to nitric oxide. Nitric oxide dilates the blood vessels and reduces the consumption of oxygen, allowing athletes to work harder and longer. The benefits of increased nitric oxide production particularly improve endurance.

The study authors evaluated the physical fitness of nine amateur cyclists at the beginning of the study. The nine cyclists were divided into two groups. The first group consumed 40 grams of dark chocolate daily for two weeks, whereas the control group consumed 40 grams of white chocolate instead. White chocolate has a much lower cocoa content and therefore fewer epicatechins.

At the end of the two weeks, the cyclists’ physical fitness — heart rate and oxygen consumption — were measured during moderate exercise and time trials. After a seven-day break, the two groups swapped chocolate types and the two-week trial and physical fitness performance measures were repeated.

What the researchers found was that when the groups consumed dark chocolate they had better overall physical fitness. The cyclists’ who consumed dark chocolate used less oxygen and were able to cover more distance during the time trials.

The study requires further larger and controlled studies to confirm the findings but suggests that eating 40 grams of dark chocolate daily could boost athletic performance — particularly among endurance athletes. Mr. Patel is currently conducting further research as part of his doctoral thesis and plans to test dark chocolate against beetroot juice as part of a comparative study.

(1) Crozier SJ, Preston AG, Hurst JW, et al. Cacao seeds are a “Super Fruit”: A comparative analysis of various fruit powders and products. Chem Cent J. 2011 Feb 7;5:5.

(2) Sudarma V, Sukmaniah S, Siregar P. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects. Acta Med Indones. 2011 Oct;43(4):224-8.

(3) Baba S, Natsume M, Yasuda A, et al. Plasma LDL and HDL Cholesterol and Oxidized LDL Concentrations Are Altered in Normo- and Hypercholesterolemic Humans after Intake of Different Levels of Cocoa Powder. J Nutr. 2007 Jun;137(6):1436-41.

(4) Djousse L, Hopkins PN, North KE, et al. Chocolate Consumption is Inversely Associated with Prevalent Coronary Heart Disease: The National Heart, Lung, and Blood Institute Family Heart Study. Clin Nutr. 2011 Apr;30(2):182–87.