If you have joined in on any workout regimen in the last couple of years, chances are good you've come across the term "HIIT training" or "High Intensity Interval Training." 

This type of training pairs short bouts of extremely high intensity cardio moves (think sprinting at 90% of your max effort) with slightly longer bouts of active recovery (like walking at a slow to moderate pace).

This style of training has been touted for it's ability to burn tons of calories in a short amount of time, speed weight loss, improve longevity,...