Tour de France: La Grande Boucle

Updated 1745 GMT (0145 HKT) July 18, 2017

Story highlights

  • Tour de France involves 21 stages in 23 days
  • Nicknamed "The Big Loop"

(CNN)The Tour de France is one of sport's most physically demanding races.

The 104th edition of La Grande Boucle -- or "The Big Loop" -- as the Tour de France is otherwise known, has the riders tackle five different mountain ranges: the Vosges, the Jura, the Pyrénées, the Massif central and the Alps.
This year's edition sees the 198 riders tackle a grueling 23-day, 21-stage, 3,540-kilometer route that takes in 23 mountain climbs and affords competitors just two rest days.
Defending champion and three-time winner Chris Froome, who lost the yellow jersey mid-race for only the second time in his career Thursday, will be looking to wrestle the race lead back from Italy's Fabio Aru.
However, Friday's short but mountainous stage -- at 101km the shortest mountain stage in the Tour's history -- doesn't play to the Briton's strength as a specialist in long, arduous climbs.