Dark chocolate has already been hailed for its positive effects on cardiovascular health. Now a study undertaken at Kingston University in the UK has found that it could help give sports enthusiasts an edge in their fitness training. A team led by postgraduate research student Rishikesh Kankesh Patel discovered that dark chocolate provides similar benefits to beetroot juice, now taken regularly by elite athletes after studies showed it can improve performance. “Beetroot juice is rich in nitrates, which are converted to nitric oxide in the body. This dilates blood vessels and reduces oxygen consumption – allowing athletes to go further for longer,” Mr Patel explained.
The Kingston University team wanted to find out whether dark chocolate could provide a similar boost, as it contains a substance called epicatechin – a type of flavanol found in the cacao bean, that also increases nitric oxide production in the body. To test the theory, they carried out a study with a group of nine amateur cyclists. The 23 year old researcher from Stratford, East London, was supervised by sport science field leader Dr Owen Spendiff and senior lecturer in sport analysis James Brouner.
After undergoing initial fitness tests to establish a baseline for comparison, the participants were then split into two groups. The first group was asked to replace one of its normal daily snacks with 40g of a dark chocolate known to be rich in flavanols for a fortnight, while the other participants substituted 40g of white chocolate for one of their daily snacks as a control. The effects of the athletes’ daily chocolate consumption were then measured in a series of cycling exercise tests in the sports performance laboratory at the University’s Penrhyn Road campus. The cyclists’ heart rates and oxygen consumption levels 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, which has now been published in 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 two-minute flat-out time trial. Mr Patel said the results opened the door for more research which could eventually lead to dark chocolate becoming a staple part of endurance athletes’ diets.
“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.”
