The 33 miners trapped underground in Chile could be reached within the next day or so. A shaft being drilled through the rock is believed to be just metres away.
The government says the first of the miners could be freed as early as next Tuesday.
It will then take up to 48 hours to hoist them to the surface one-by-one.
The Chilean Health Minister, Jaime Manalich, spoke at the mine head.
“For the last few days, we’ve been asking all the miners to do much more intense regular physical activity, in order to test their reactions to stress, to simulate the emotion and the tension that they’ll experience during the rescue phase,” he said.
One of the most challenging rescue operations in mining history is approaching its most crucial phase.
The engineers will need to decide whether the miners can be pulled up through the exposed rock, or whether the shaft must first be lined with metal tubing.
At ‘Camp Hope’ above ground the families have been doing their own exercises to fight off the desert cold.
Rehearsals have been taking place for “D-Day”. As soon as the miners surface they’ll be whisked to hospital for thorough medical examinations.