Fernando Alonso has returned to physical training in preparation for the start of his 2015 race campaign in Malaysia.The Spaniard is sitting out the Melbourne opener next weekend as he waits out a pre

Fernando Alonso has returned to physical training in preparation for the start of his 2015 race campaign in Malaysia.

The Spaniard is sitting out the Melbourne opener next weekend as he waits out a precautionary 21-day period to prevent the potentially fatal, post-concussion 'second impact syndrome'.

What is becoming clear is that what happened precisely at turn 3 on the final day of the second Barcelona test might never be known - by anyone.

FIA investigators are now deep into their analysis of the mysterious McLaren-Honda crash, but what the telemetry shows is odd and the only person who might actually know - the Spaniard himself - cannot remember.

Auto Motor und Sport claims the telemetry shows Alonso's highest speed in the corner as 215kph, but then he inexplicably hit the brakes, downshifted, but maintained apparent control of the Honda-powered MP4-30.

Once his speed dropped to 135kph, Alonso steered to the right and struck the wall at 105kph. It is this that Sebastian Vettel observed as "strange".

It is known that Alonso was at some point unconscious, but the car was only lightly damaged and the 33-year-old's helmet showed not a single scratch.

What the FIA has reportedly ruled out is the electric shock theory, backed not only by the telemetric evidence but also because Alonso's medical tests showed no sign of a symptomatic enzyme.

Whatever actually happened, McLaren claims Alonso is currently clear of any "injury" or "medical issue", and "entirely healthy from neurological and cardiac perspectives alike".

So he is already preparing to travel to Malaysia in three weeks. Spanish sources reveal he will not fly to Australia next week, even just to watch.

The Spanish sports daily Marca reports that, given his all-clear by doctors, Alonso will have no more medical tests except the mandatory ones administered by the FIA ahead of his return to the cockpit in Malaysia.

Created by FIA medical delegate Jean-Charles Piette, Alonso will have to undergo reflective, cognitive and memory tests that match his previous 'control' scores to a value of 95 per cent.

In the meantime, his doctors have barred him from his favourite sport - road cycling - but he is allowed to run on a treadmill, swim, or work out in the gym.

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