The NY Times covers a 7-minute workout (with link to free article) that utilizes the growing trend of HICT (High Intensity Circuit Training). HICT enjoys growing evidence that short, intense workouts give similar health benefits to longer ones.
http://well.blogs.nytimes.com/2013/05/09/the-scientific-7-minute-workout/
http://well.blogs.nytimes.com/2013/05/09/the-scientific-7-minute-workout/