Intensive course and and long training is highly recommended before taking the exam. Also it is adivsed to work even several years in ITIL environment to deeply understand what the itil master is about. There are of course intensive courses organized by various companies. The courses should prepare candidates to Service Manager's certification, however even intensive training is not so valuable as many years of ITIL experiences.
Average training is 10-15 day in course lerning with lot's of materials to self-study after the class. During the class training emphasis is on practical case studies which is about 60% of the whole manager's curriculum. Other remaining 40% is theory. ITIL Manager Certification is a pass for wide career opportunities including such roles as service architect or line service manager. This is the reason for which - during the training - candidates have to present their 'solutions' to complex problems and have to proofe their communication and team building skills.