The IAAF has announced that it will be introducing a mixed 4×400 metres relay and a midnight marathon at the 2019 World Athletics Championships in Doha Qatar.

The announcement was made by IAAF president Sebastien Coe speaking ahead of today’s season-opening diamond league meeting.

The mixed event has been a staple at the world under 18 level in recent editions and is now part of the senior setup which forms part of a big shake up of the traditional scheduling of the championships.

The decathlon and heptathlon will be run concurrently — a first for the world championships — with their respective event-ending 1500m and 800m finals both starting after midnight.

Marathon and race walking events will also start at 11:30pm local time when temperatures in the gulf state remain very hot and humid.

In the world championships which runs from September 28 to august 6, split evening sessions, with a one-hour break, will replace the previous daily format of straight morning-evening sessions.