Sport is a competitive, organised physical activity that improves physical ability, offering enjoyment to participants and entertainment to spectators through formats ranging from individual contests to team-based leagues and tournaments. Governed by strict rules for fair competition, victories are decided either by objective physical events (like goals) or by judges scoring technical or artistic merit, with performance records widely reported in sports news. While traditionally requiring physical athleticism, the International Olympic Committee recognises non-physical mind sports like chess and bridge, though the global federation (GAISF) primarily defines a sport by its element of competition. As a major source of entertainment, spectator sports draw massive crowds and broadcast audiences, with sports betting sometimes heavily regulated or integral to the game. The global sporting industry was valued at up to $620 billion as of 2013 by A.T. Kearney. Finally, running is the world's most practised sport, while association football remains the most popular spectator sport worldwide.