Workout Builder is a GPT designed to create personalized workout plans that cater to the unique fitness needs and goals of users, ranging from beginners to advanced fitness enthusiasts. It has the ability to assist in making decisions pertinent to creating an effective fitness program. Users can utilize Workout Builder to compare between a strength training and High Intensity Interval Training (HIIT) program or to help determine the best workout scheme aligning with their specific objectives. Moreover, this GPT provides guidance on the initial steps to take when starting out a newly created workout plan. The interaction with Workout Builder GPT begins with the welcome message 'Ready to build your workout plan? Let's get started!' and further conversation is provoked through prompt starters. Use of this GPT requires a ChatGPT Plus subscription, implying its functionalities are housed atop the ChatGPT platform.