Dark Chocolate...

Lauren Harrell

Article Summary

Runner's World

Dark Chocolate is Good For Your Heart And Your Workout

By: Nova Sienkiewicz

March 31, 2016

In her article “Dark Chocolate is Good For Your Heart And Your Workout”, Nova Sienkiewicz (2016) describes how Kingston University in England found epicatechin, a nutrient found in cocoa beans, and claims that this nutrient will enhance performance in short distance runs. The study performed by the university compared the overall fitness level and the oxygen uptakes of nine healthy cyclists during twenty minutes of cycling, and during a two-minute full-speed sprint. The cyclists were split into two groups, one was given 40 grams of white chocolate, which does not contain epicatechin, and the second was given 40 grams of dark chocolate, which contains the nutrient epicatechin. After this test was completed, the participants swapped groups, and the tests were given again two weeks later. The groups that consumed dark chocolate during the sprints traveled a tenth of a mile longer than their initial tests (in the initial tests no chocolate was consumed). Additionally, those who consumed dark chocolate daily during the tests had a 21 percent improvement in oxygen intake and those consuming white chocolate had an 11 percent improvement compared to tests without the consumption of chocolate. In conclusion, dark chocolate might enhance a runner’s endurance for short runs, but probably won’t help runners improve prolonged race times.

Article Critique

The author of this article, Nova Sienkiewicz, is an editorial intern for the magazine Runner’s World. Based on available information provided by the magazine, it does not appear that she has a degree in health sciences, and does not have any affiliations with Kingston University. Even though the author may not have the background to make scientific claims, she never draws her own conclusions from the study performed. Sienkiewicz clearly states the results of the Kingston University study, and quotes the conclusions drawn from Jane Burrell Uzcategui, M.S., R.D., a nutrition instructor at Syracuse University. Scientific evidence (the study by Kingston University of 9 cyclists) was provided for the conclusion that dark chocolate enhanced performance and improved oxygen intake in cycling. However, Uzcategui states that dark chocolate may enhance a runner’s endurance during moderate intensity, short duration runs, but no study or explanation is given to show how the study on the cyclists may transfer over to an exercise like running. In addition, this article only references this one study performed, and does not provide any other examples of studies or science that may back up this claim of dark chocolate boosting your performance in short runs. With that said, the author does make sure to remind the readers that we should be mindful when thinking about adding more dark chocolate to our diets, being aware of the portions we eat, how often we consume it, and what results we might expect in our athletic performance. Lastly, the article fails to mention how much chocolate is the perfect amount to achieve these results. Overall, Sienkiewicz provides a moderate amount of evidence that dark chocolate might improve a runner’s endurance during short runs, and she achieves this in a well-written informative article that would be a good read for anyone interested in nutrition and exercise.


Sienkiewicz, N. (2016, March 31). Dark Chocolate is Good For Your Heart And Your Workout. Retrieved April 04, 2016, from http://www.runnersworld.com/nutrition/dark-chocolate-is-good-for-your-heart-and-your-workout