A soldier from the Scots Guards fainted during the 2010 Colonel's Review (Picture: PA).
A military cardiologist says consuming more salt on the day of parades could prevent soldiers fainting while working in the heat.
A number of guardsmen passed out during a rehearsal for Trooping the Colour last month.
However, for the Trooping the Colour ceremony itself, new protocols were taken involving a higher salt intake, with the result being no soldiers fainting.
Service personnel were encouraged to increase their daily salt intake by up to ten grams for a week, going against the NHS recommendations of a maximum of six grams a day for adults.
Watch: A number of guardsmen fainted during Trooping the Colour rehearsals this year.
The Royal Army Medical Corps' Major Iain Parsons told the Times an increased salt intake "increases the plasma volumes, the amount of water in the blood", and acts as "a bit of a trick to hyper-hydrate you".
It means a person can stand up for longer in increased heat.
Maj Parsons also said the traditional pre-parade big breakfast could also be one of the causes of soldiers' fainting at the events.
According to the cardiology doctor's research, consuming a heavy meal before a parade directs the blood flow to the gut instead of pumping around the body in an effective way.