The HIIT exercise protocol according to Little and co-workers (2009)

I have been interested in High Intensity Interval training (HIIT) ever since I have read the Tabata et al., 1996 paper on HIIT (Med Sci Sports Exerc. 1996 Oct;28(10):1327-30.)

I have summarised the protocol and results from the famous study performed by Little et al., 2009  (J Physiol. 2010 Mar 15;588(Pt 6):1011-22. Epub 2010 Jan 25. ). 

This protocol is more practical than the original Tabata study as no specialised exercise equipment is needed. 

Subjects underwent HIIT for 3 times a week (monday, wednesday, and friday).

Prior to training, each subject underwent 3 minutes cycling at medium intensity.

The subjects started off with 8 high intensity intervals for the first 2 weeks,  

The next 2 weeks, the intervals was increased to 10, then the next 2 weeks they were increased to 12 intervals.

Each high intensity interval was for 60 seconds, followed by 75 second low intensity exercise.

The results were interesting:

Enzymes linked to improved muscle performance and increased metabolism and genes involved in glucose usage in the muscle were elevated significantly.