Two Jewish doctors are running a medical trial to help Jewish athletes.
Dr Robert Fern, a gastroenterologist at Barnet General Hospital and Dr Marc Wittenberg, an anaesthetist at the Royal Free Hospital in London, are conducting the experiment on members of the football and futsal (indoor five-aside football) teams, from this year's Maccabi Great Britain squad.
As part of the trial, which began on Sunday, the players, who will take part in the 13th European Maccabi Games in Vienna next month, took either nitrate or an inactive placebo, followed by tests to monitor the impact on muscle tissue.
Nitrates have already been shown in small studies to improve performance in some sports, but the two doctors, who are leading the British medical team at the games, believe this is the largest investigation of its kind.
They hope that the study, which is being carried out in partnership with University College London, will be used to set up a larger sample size, using squad members at the Maccabiah Games in Israel in 2013.
Dr Fearn, a member of Hampstead Garden Suburb Synagogue, said he hoped the project would "pave the way for additional work in the Jewish sporting world".