The Tour de France started this week, which is probably the toughest race in the world. 170 cyclists attempt to race 21 days, with only two one-day breaks, about 120 miles a day. There’s a fastest sprinter competition, fastest mountain climber, the overall winner, and stage winners each day. Plus, lots of crashes. There’s already a guy who has been going six days with a fractured back. Watch on NBCSN.