The countdown to Chris Hoy?s world record attempt is entering its final few days. The Scot will fly in to La Paz, Bolivia this Friday, just one day before attempting to break the world record for the kilometre time trial.

The current record of 58.875 seconds, set by Frenchman Arnaud Tournant of France, is within Hoy?s grasp even though the four-time world champion admits he?s going in to the unknown.

The track at La Paz sits at 3,408 metres, an altitude that Hoy has never before been to, and with only two-thirds of the oxygen present at sea level, the intense effort holds certain risks, ?I wouldn’t say I’m scared, but I am apprehensive. There are risks involved, and I am aware of them, but I’ll have full medical support,? he said.

After his attempt in 2001, Tournant passed out, and only fully came round some 20 minutes later. Hoy will have an oxygen mask waiting for him on the finish line, with a body bag with it?s own oxygen supply present in case of an emergency.

Not wanting to acclimatise due to the anaerobic nature of the event, Hoy is currently in Fort Lauderdale, Florida, training on the 333m concrete track, ?we’ve got a relaxed atmosphere, with everything tailored to what I want,” Hoy said.

The record attempt, that is costing around £40,000 may yet get a large crowd packed in to the decrepit velodrome in southern America. It is being shown live on Bolivian TV while a BBC documentary crew have been tailing Hoy for several Months.