More than 1 million people have applied for tickets for next year's World Athletics Championships in London where greats Usain Bolt and Mo Farah will compete for the final time on the track.

Jamaican Bolt, who completed a triple-triple of 100 meters, 200 meters and 4x100-meter relay at last month's Olympic Games, and Briton Farah, who retained the 5,000­ ­meters and 10,000 meters titles in Rio, have both said next year's ­World Championships in London will be their last.

Bolt plans to hang up his spikes after the event while Farah intends to switch his focus from the track to the marathon.