Short for High Intensity Interval Training, anyone doing this? Looks interesting, as I really struggle to find the time to exercise 5 times a week.
http://www.bbc.co.uk/news/magazine-37249021
http://www.bbc.co.uk/news/magazine-37249021

Though having said that, when interval training, music in the background is nice but you won't really be able to focus on it as you're either going for it or wishing the rest periods were longer