The Tokyo Olympic marathon course will get a test on May 5 when runners take to the streets in the northern city of Sapporo.The Olympic marathon was moved to the Sapporo due to organisers concerns over the summer heat in Tokyo, long before the Covid-19 pandemic forced a postponement of the games.Yasuo Mori, Tokyo 2020 deputy executive director of the Games Operations Bureau said at a pre-event press conference that one of the most difficult challenges now will be maintaining space between people on an open marathon course.