Certificate III in Fitness (Gym Instructor) is the entry level qualification required for employment in the Fitness Industry. This allows an instructor to Assess, write programs, teach exercises, and assist people with their gym programs. Certificate III is also the pre-requisite for Certificate IV (Personal Trainer). Certificate IV is a higher level qualification designed to increase the depth of knowledge and skill levels required for more 1-on-1 training. You need Certificate IV to access Personal Training insurance.
This is the most commonly asked question, but one that depends entirely on the individual. It takes you as long as it takes to get through the lecture material, complete the practical assessments, and take the online exams. If you study the lectures full time (approx 15 - 20 hours per week) it should take you about 2-3 weeks. If you study the lectures in a more part time format it would be more like 4-6 weeks to get it done.
Assessments for both Certificate III and Certificate IV cover a wide range of formats to fully prepare you for each topic. Students are guided as to how to study and prepare, with practice assessments and tutoring services available. The assessments are focused on the pracitical application of learnt theory to ensure people are "job ready".