We attach a link to a recent blogpost by Dr. Mercola (www.mercola.com) highlighting the a recent study conducted by Brett Klika from The Human Performance Institute in Florida (HPI) and Chris Jordan, director of exercise physiology at the HPI evidencing the benefits of high intensity interval training.
http://fitness.mercola.com/sites/fitness/archive/2017/01/20/can-7-minute-exercise-help-keep-you-fit.aspx