High-Intensity Interval Training, or HiiT, is a term used to describe short periods of intense exercise punctuated with short recovery periods. HiiT workouts often range from between 10-30 minutes. Despite how short the workout is, these types of workouts can provide a plethora of health benefits, including burning calories, increasing your metabolic rate, and helping you gain muscle and lose fat. Interested in trying out a Hiit workout? Lyndsey Fielding, owner of Fielding FamilyFit, walks you through a HiiT routine with modifications for more advanced athletes and beginners.