Chris Froome's Tour de France rivals Nairo Quintana and Alberto Contador have resolved to attack the race leader in the Alps.
Team Sky's Froome was the master of the Pyrenees after crushing the opposition in the first summit finish of this year's race.
Second-placed Quintana says he has trained to be consistently strong throughout the three weeks and he is known for finishing with a flourish in the final week of a Grand Tour.
"I don't know if we'll overtake Froome, but we'll try," he said. "Even though it would be satisfying to be on the podium in Paris, the main aim we're working for is the yellow jersey."
Quintana's is second at 3min 10sec but his Movistar teammate Alejandro Valverde is fourth at 4min 02sec.