Kingston University
Dark chocolate has already been hailed for its positive effects
on cardiovascular health -- and now a study undertaken at London's Kingston
University has found the tasty treat could help give sports enthusiasts an
extra 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 team from the British university 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, Mr Patel carried out a study with a group of
nine amateur cyclists. The 23 year old researcher 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 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 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. "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."
Mr Patel carried out the study as part of his undergraduate
sport science degree at Kingston University, and is now conducting further
research into dark chocolate as part of his doctoral thesis.
He is hoping to
discover the optimal flavanol level in dark chocolate for boosting athletic
performance.
"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.
"We are also investigating the optimal level of flavanols. 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."
Dr Owen Spendiff, who has conducted studies around beetroot
juice and athletic performance, said that Mr Patel's work showcased some of the
cutting-edge research being carried out within Kingston University's sport
science facilities.
"Rishikesh's findings are really interesting, as he
has proven the exercise benefits of dark chocolate for the first time," he
said. "The fact he began his research into dark chocolate as an
undergraduate and is now carrying that forward at postgraduate level here
really demonstrates what our sport science students can achieve."
Meanwhile sport analysis lecturer James Brouner -- who in his
spare time pounds the pavements as an ultra-distance runner -- said that the
research suggested dark chocolate could offer particular benefits to endurance
athletes.
"From a performance perspective, making an athlete more
efficient can have major advantages in long duration steady-state
exercise," he said. "With so many athletes consuming beetroot juice
to achieve this gain but complaining of the palatability, dark chocolate could
have a similar effect but with the additional benefit of tasting good too.
"When performing endurance-based activity, being as economical as possible
in energy provision is key to enhancing your performance. From our results, the
consumption of dark chocolate has altered the participants' response to the
activity and therefore could enhance their endurance performance."