Many top athletes, facing a world outdoor championships in Doha that do not start until late September, will be competing less, if at all, during the indoor season, coaches and athlete representatives have told Reuters.

FILE PHOTO: Athletics - IAAF Diamond League Final - King Baudouin Stadium, Brussels, Belgium - August 31, 2018 Christian Coleman of the U.S. celebrates after winning the men's 100m REUTERS/Francois Lenoir/File Photo