Read the passage. training for the tour a group of bikers the tour de france is one of the most famous bicycle competitions in the world. for twenty-one days, cyclists race through the streets and up the mountains of france. training for the tour de france is just as intense. athletes must prepare for months ahead of time. some ride their bikes for as many as twenty to thirty hours per week. when not cycling, they exercise and lift weights to build their strength and endurance. in addition, cyclists follow a strict diet to stay in peak condition. what is the main, or central, idea of the passage?