Group/Personal Trainer: TAFE/Private institution for a CIII/CIV respectively. Over time good trainers complement these with professional certifications e.g. 'Strength and Conditioning', 'Weightlifting' etc. Some also go one to study physiotherapy/similar at university.
Physiotherapist/Sports Manager/Sports Psychologist/etc: University study. Physio is the easier industry to break into and probably has better guarantees of income. Whilst dedicated Sports Management/Sports Psychology/etc degrees are available you are probably better to do a plain Management or Psychology degree and then just apply for jobs in the Industry.