You may be confused about what HIIT is & why the workouts are so popular.
Before your next gym session, read about HIIT. High-intensity interval training HIIT which makes one of the most popular phrases used to describe it, "HIIT training," totally redundant.
HIIT isn't only jogging or weightlifting. HIIT is a framework that trainers can use to construct varied routines based on equipment, participant experience, time, & difficulty.
HIIT workouts consist of short bursts of intensive work followed by rest or active recovery.
For HIIT to be effective, participants should work near or at peak effort during intervals & back off during breaks. Some trainees employ HIIT as the cardio component of their workouts instead of LISS like long runs or cycling.