Six soldiers are taking part in a marathon 250-mile open water swim in order to raise funds for injured servicemen.
If you're going to race horses against motorbikes, you might want to practice - especially if it involves jumping through fire.
Members of the Armed Forces have been practising their routines for this year's military show.
Three and a half thousand soldiers are preparing to take part in the Olympics. They will not be competing. Instead they will be helping to fix a failure by the very firm hired to secure the Games.
A former worker from that firm, G4S, told ITV News the contract was a total rush job from the beginning, and the faliure is no shock to her.
The Mayor, Boris Johnson, has defended the decision to bring in the troops saying it's 'belt and braces stuff'.
Critics say the situation is a shambles. However, nobody from London 2012 or G4S was available for an interview today. The troops are being brought in after G4S admitted yesterday they had failed to recruit enough people. Our Olympics Correspondent Simon Harris reports.
The Home Office is expected to reveal more details today about reports that around three and a half thousand extra soldiers are being drafted in to help provide security for the Olympics.
GS4, the private contractor tasked with supplying security for the Games which start in a fortnight, has said it has 'encountered some issues in relation to workforce supply and scheduling'.
"This has been an unprecedented and very complex security recruitment, training and deployment exercise which has been carried out to a tight timescale.
"We have encountered some issues in relation to workforce supply and scheduling over the last couple of weeks, but are resolving these every day and remain committed to providing a security workforce for the start of the London 2012 Games."
– G4S spokesperson
"Our planning with Locog and other security agencies allows for a variety of contingencies which have been reviewed in the build-up to the Games. We accept that the Government has decided to overlay additional resources. We remain committed to keep London 2012 safe and secure."
– Home Office spokesperson
"We have agreed to offer help to G4S by revising the level of military support.
The Government are committing £553 million for venue security and we remain confident that we will deliver within budget."
"The focus of the Government and everyone involved is on delivering a safe and secure Games. G4S are Locog's lead contractor for venue security and are being supported by the military.
"Our approach is intelligence-led and risk-based, and we retain the ability to be flexible in our response."
Fo rmore details and analysis visit the National ITV News website.
The inquest into the death of a soldier from Watford who was killed in Afghanistan is to be held today.
Private Thomas Lake from 1st Battalion The Princess of Wales's Royal Regiment, was killed in Afghanistan on Sunday 20 November 2011. **
Private Lake was taking part in a patrol of the Nahr-e Saraj district of central Helmand when he was caught in an explosion.
At the time of his death, Private Lake's mother Carol said, ""Tom was a wonderful son and I will miss him more than I can say....Tom loved the Army and was so proud to be a soldier; he died doing something he loved and believed in. I will always be proud of my boy."
While the rest of the capital was sleeping, hundreds of soldiers rode on horseback through the streets of London to rehearse the State Procession for the Queen's Diamond Jubilee.
Members of The Household Cavalry Mounted Regiment rode at dawn from the Palace of Westminster along Whitehall to Trafalgar Square, then through Admiralty Arch and along the Mall to Buckingham Palace.
The route was lined with personnel from the Royal Navy and Royal Marines, Foot Guards and Massed Bands of the Household Division, the Princess of Wales's Royal Regiment and the Queen's Colour Squadron of the Royal Air Force. In total, some 2,000 servicemen and women took part in the rehearsal.
Thousands of flag-waving well-wishers are expected to turn out for Tuesday's spectacle.