Via NY Times
This article is based on a paper published here. The author’s advocate that a 7 minute high intensity workout that is just as effective as longer workouts.
To address the limitations of traditional exercise protocols and provide an effective and efficient program for our clients, one of the exercise strategies we use is high-intensity circuit training (HICT) using body weight as resistance. Our approach combines aerobic and resistance training into a single exercise bout lasting approximately 7 minutes. Participants can repeat the 7-minute bout 2 to 3 times, depending on the amount of time they have. As body weight provides the only form of resistance, the program can be done anywhere.What the NY Times article misses is that you can't really do this in 7 minutes. You should do multiple reps for 20 minutes.
Because most individuals may not be able to execute the program at an intensity significantly greater than 100% of their V?O2max, following the established ACSM guidelines for high-intensity exercise of at least 20 minutes is recommended (3). This may require multiple repetitions (or circuits) of a multistation exercise circuit.