Day four of the World Athletics Championships gets underway in Japan with the heats of the men's 800m. Olympic champion Emanuel Wanyoni is the one to beat, but Great Britain's Max Burgin has had a fantastic season and is aiming for a place on the podium. Meanwhile, Venezuela's defending champion Yulimar Rojas returns to action after 18 months out through injury in triple jump qualifying. She's a three-time world champion, so could a fourth title be on the cards?