Training for a major event like the ElectronicSportsWorldCup (ESWC) involves practising with friends and other gamers (locally or online), or competing at smaller tournaments to build up competitive gaming experience.
For a privileged few, including UK Counter Strike team 4Kings (who will be representing the UK at the upcoming ElectronicSportsWorldCup in Paris), and world famous professional gamer Fatal1ty, this is already a reality.