This form of training is so flexible that it has produced an endless number of training options and several different names to describe it. High-intensity interval training (or HIIT or HIT) is likely the most common name but several other labels exist as well, including sprint interval training (or SIT) or high-intensity interval exercise (or HIIE).
One other aspect of flexibility around HIIT relates to the style of exercise. Most of the original HIIT workouts focused on what many call “cardio HIIT” in that it utilizes traditional cardio-based exercise options such as running and cycling. However, much of the contemporary use of HIIT is perhaps best described as “body weight HIIT” and includes some combination of resistance exercise and calisthenics. Most of the research to date is based on cardio types of HIIT but all signs point towards both forms of HIIT being highly beneficial.