The Mail said:
And the Express claimed:
The articles began with similar claims. Jo Willey in the Express said:
Chocoholics who shun the gym can celebrate – a little bit of dark chocolate can improve health in much the same way as exercise.
Tamara Cohen in the Mail said:
Eating dark chocolate improves athletic performance just as much as exercise, a study has revealed.
In each article, it was only in the third paragraph that it was revealed that this research was based on experiments conducted on mice. At the end of the Express' article, it says:
Could this be extrapolated to humans? “It is something we hope to identify in future studies,” said Dr Malek.
So the tone of these headlines and articles isn't really justified.
Indeed, the NHS Behind the Headlines view is that the newspapers 'overreacted':
These misleading headlines refer to the findings from a small study in 25 mice. The relevance of these findings to humans is uncertain...
These findings provide evidence that giving mice epicatechin can lead to increases in their muscular performance that are similar to those obtained by regular exercise.
Contrary to the statements made in the news reports, it is unclear whether the chemical would have the same effect in humans, and further research would need to investigate this.
Also, epicatechin is found in dark chocolate, but chocolate was not tested in this research. It is unclear how much would need to be consumed to get the levels that were given to these mice, or the appropriate level of epicatechin needed to get a similar response in humans.
In conclusion, they say:
the study does not show that eating dark chocolate is beneficial, or that it is a substitute for exercise in humans, attractive though the idea is...Such statements are not backed up by this study.