Gino and I were talking about this newspaper article this morning that was on the front page of the Life section. On HIIT or high intensity interval training.
If you look up scientific journals, an actual HIIT workout is actually running or cycling a set distance a number of times. For example, running 1 kilometer 10 times, or cycling 3 kilometers 5 times. Also popularly know as 'interval training' amongst runners.
While he was still competing in triathlons Gino says he used to run 10 x 1 kilometer going every 5 minutes. If he finished the kilometer in 3:30 min, he will have 1:30 min rest before attempting the next. If he finishes the kilometer in 3:45 min, it means he will have a shorter period of rest. That HIIT is what research papers usually investigate and publish it's results.
What the author and the interviewed health professionals describe is commonly known as 'circuit training'. Of course there are some similarities where you do certain exercises intensively for a fixed amount of time. But I guess HIIT sounds a lot better than circuit training. That's a good way for gyms and personal trainers to get people to exercise and train.