Ashton Eaton of the United States, the favorite in the decathlon, got off to a good start on Day 1. He will look to lock up his second consecutive gold medal. The final event, the 1,500 meters, goes off at 8:45 p.m. Joe Kovacs leads a threesome of Americans looking to medal in the shot-put. Ryan Crouser and Darrell Hill are the others. The 400-meter hurdles for men and women are both wide open. Watch Kerron Clement and Dalilah Muhammad of the United States.
