In 2013, the foremost competition in athletics was the 2013 World Championships in Athletics in Moscow. The International Association of Athletics Federations will hold two other global level competitions this year: the 2013 IAAF World Cross Country Championships and the 2013 World Youth Championships in Athletics. The IAAF World Cross Country Championships will return after its move to a biennial format. The Diamond League enters its fourth year as the foremost seasonal track and field series.