Athletics at the 2016 Summer Olympics – Men's 400 metres
The men's 400 metres event at the 2016 Summer Olympics took place between 12 and 14 August at the Olympic Stadium.
Summary
was the Olympic champion in 2012 and was in good form before the competition with a run of 44.08 seconds placing him second on the global rankings. The 2008 Olympic champion LaShawn Merritt topped the lists for the season as the only man under 44 seconds. Wayde van Niekerk ranked third and was the 2015 World Championships winner. At that competition the trio had all run under 44 seconds for medals and were the principal challengers to the Olympic title. Two younger athletes, Baboloki Thebe and Machel Cedenio, were the next fastest athletes to enter.James was the fastest in the first round with 44.93 and Cedenio was the other heat winner under 45 seconds. The 2016 World Indoor Champion Pavel Maslák, David Verburg and Rafał Omelko qualified as fastest losers. Former European champions Martyn Rooney and Kevin Borlée were eliminated.
In the semi-finals, James had a season's best time of 44.02 to win the round nearly two tenths ahead of Merritt. Cedenio won the 2nd semi final ahead with van Niekerk second. Bralon Taplin won the third semi final. Fastest loser qualifiers Karabo Sibanda, Matthew Hudson-Smith and Ali Khamis all set personal bests.
In the final, the three favorites James, van Niekerk and Merritt led from the start. By the end of the turn, van Niekerk had a clear 2 metre lead, Merritt just slightly ahead of James who had closed the gap during the turn. Cedenio was another four metres back, with Taplin another metre back. In the home straight van Niekerk increased his lead while James overtook Merritt, finishing second and third. Cedenio was fourth, Taplin faded, and in lane 1, 18-year-old Karabo Sibanda finished fifth.
Van Niekerk set a new world record of 43.03 seconds, beating Michael Johnson’s previous record set at the 1999 World Championships by 0.15 seconds. Johnson was in the stadium, working in the British commentary booth.
Cedenio set the national record for Trinidad and Tobago and Ali Khamis in sixth set the national record for Bahrain.
Records
Prior to this competition, the existing World and Olympic records were as follows.| World record | 43.18 | Seville, Spain | 26 August 1999 | |
| Olympic record | 43.49 | Atlanta, United States | 29 July 1996 |
| Area | - | - | - |
| Area | Time | Athlete | Nation |
| Africa | 43.48 | Wayde van Niekerk | South Africa |
| Asia | 43.93 | Yousef Ahmed Masrahi | Saudi Arabia |
| Europe | 44.33 | Thomas Schönlebe | East Germany |
| North, Central America and Caribbean | 43.18 | Michael Johnson | United States |
| Oceania | 44.38 | Darren Clark | Australia |
| South America | 44.29 | Sanderlei Parrela | Brazil |
The following new world, Olympic and African record were established during this competition:
| Date | Event | Athlete | Time | WR | OR | AR |
| 14 August | Final | 43.03 s | WR | OR | AR |
The following national records were established during the competition:
| Country | Athlete | Round | Time | Notes |
| Slovenia | Semifinals | 45.07 s | ||
| Bahrain | Semifinals | 44.49 s | ||
| South Africa | Final | 43.03 s | ,, | |
| Trinidad and Tobago | Final | 44.01 s | ||
| Bahrain | Final | 44.36 s |