By Matt Majendie BBC Sport in Paris

With the Tour de France in its centenary year, tradition is arguably more important than ever.

Only one cyclist has ever failed the pre-race medical Tour history guide

And one obstacle all 198 riders in the Tour de France have to overcome before racing shows no signs of being scrubbed from the calendar - the pre-race medical.

Every rider takes their turn to be checked and double checked by the Tour's doctors.

Australian rider Stuart O'Grady's Credit Agricole team were the first to line up for this year's medical checklist

And the sprinter, among the favourites for the coveted green jersey, told the BBC Sport website: "It's just one of those formalities I'm afraid. Us guys would rather not do it but the rules are rules and it only takes up a few minutes of our time.

"They're pretty spot on with it - you're weighed and measured, they check your lung capacity and your heart rate, and then have a quick chat with you before sending you on your way."

But we followed this year's Giro d'Italia winner Gilberto Simoni through the major steps of his medical carried out by Dr Pascal Rivat.

1. Height and weight

Every rider has to be weighed and measured - that part of the medical really is a formality.

The details are noted by one of Tour doctors' medical assistants and registered in the official records.

Dr Rivat on Simoni: "Obviously everything is in order. In fact only one rider has failed their medical before - Albert Bouvet 30 years ago and he went on to become part of our Tour medical team."

2. Lung test

Cyclists have notoriously large lung capacity, partially due to their level of fitness and also because of a lot of altitude training.

Each rider must simply blow down a tube - not dissimilar to a breathalyser test - from which a reading of their lung capacity is taken.

Dr Rivat on Simoni: "A lot of riders laugh and joke before this one, with all their team-mates around them.

"But it is extremely important as, through it, we can detect any respiratory problems, which would be dangerous in competition. In Gilberto's case, there are none."

3. Fitness chat

Giro d'Italia winner Gilberto Simoni passes with flying colours

Every competitor lies on what is effectively a doctor's couch where they are asked if they are carrying any injuries or have suffered from any injuries.

Again this is a formality although legally the Tour organisers need to ensure every rider they allow on the road is in peak physical shape.

Dr Rivat on Simoni: "Again there are no problems here. But I always stress to riders not to cover up any complaints as they will only come back to haunt them later in the race."

4. Heart tests

While still reclining on the doctor's couch, riders have their heart beat tested with a stethoscope.

The doctor then tests the individual's blood pressure.

Then a series of wires are in turn attached to each rider and a read-out is taken of the rider's heart and ensures there are no irregularities.

Dr Rivat on Simoni: "The readings are usually higher than normal with the nervous energy but Gilberto seems relaxed and in perfect condition. Time for the next rider."