How long should HIIT workouts be for effectiveness?
Due to the extremely intense nature of HIIT workouts, they typically last for no more than 20 minutes. An effective HIIT workout can actually be done in about 10-12 minutes if you structure it correctly. If you can last for longer, chances are it is not intense enough.
An example of HIIT for beginners would be sprinting for 20 seconds, followed by walking or resting for 10 seconds. This is repeated for 20 cycles for a total of 10 minutes. As we progress in fitness level, we can increase the number of cycles or the "duration-ratio" of the high-low intensity portion of the workout. For instance, the workout will be more challenging if we sprint for 30 seconds and rest for 10 seconds.
While many factors seem to come into play when looking at HIIT's effectiveness in burning fat, a prominent reason for this is because HIIT is designed to always challenge and keep the body guessing, as we can easily alter the parameters to suit our fitness levels.