A McMaster University kinesiologist has done a lot of research on interval training. Here are some links to articles written about this in the mainstream media.
http://www.cbsnews.com/stories/2005/06/ ... 5228.shtml
http://thyroid.about.com/od/loseweights ... ercise.htm
But for the full academic research, google "Journal of Applied Physiology" and enter "Martin Gibala" in JAP's search engine.
Really interesting stuff. I've been skimming through it all afternoon instead of working. Oh well... I am a journalist, so I guess I can justify it as research.