A new study suggests that eating a small amount of dark chocolate could boost your riding speed

Christmas can wreck your ideal diet. The temptation to eat all the wrong things and in huge quantities can undermine your winter fitness plans. Fortunately, scientists have provided an excuse – they say that dark chocolate can help you cycle faster.

In an experiment that you might want to try yourself, cyclists were given 40g of chocolate every day for two weeks. Some of the enthusiastic volunteers got dark chocolate, the others got the white variety which contained the same number of calories.

That was the fun part. Next came the hard work.

They had to do a ramp test in the lab – pedalling at increasing intensity until they were exhausted. After a rest, they had to ride for 20 minutes at 80% of their maximum and then push themselves through a two minute time trial.

But their efforts were worth it – at least, it was for those who’d been enjoying the dark chocolate. The results form their time trials were significantly higher. Compared to the white chocolate eaters, they covered 13% more metres and compared to themselves before they’d started the experiment, they rode 17% further.


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What’s more, special tests showed that the dark chocolate improved their bodies’ ability to use oxygen. Their heart and breathing fitness were a whopping 21% higher than before the experiment began and 11% higher than for those on the white chocolate diet.

So the scientists have shown there’s something in dark chocolate that boosts cycling more than white chocolate and it’s not just the colour. It’s actually an ingredient that has a similar effect as the popular but less appetising or convenient supplement, beetroot juice.

The scientists get quite excited about these results, in their own, academic kind of way. “This is of great interest given the popularity of dark chocolate [which is] often associated with food categories of high palatability and indulgence,” they say.

Although people have been saying for years that dark chocolate is good for your heart, this is the first experiment to see how it affects time trialling, albeit only for two minutes.

And before you start experimenting yourself, not all dark chocolates have the same amount of the magic ingredient. The scientists used Dove (called Galaxy in the UK) because they knew it contained the right stuff.

So now you can enjoy Christmas and include a small bar of dark chocolate every day as part of your fitness regime.

Dark chocolate supplementation reduces the oxygen cost of moderate intensity cycling by 
Rishikesh Kankesh Patel, James Brouner and Owen Spendiff, is published in the Journal of the International Society of Sports Nutrition, volume 12, 2015.

Max Glaskin is an award-winning freelance journalist who tweets about cycling and science as @CyclingScience1 and is the author of Cycling Science (published by Frances Lincoln UK, Chicago University Press USA, and seven other languages). He likes dark chocolate, too.