I'm not sure how they tested it but I don't think they really did. The blades don't even come close enough in size to being able to blend the food. The blades are probably one third of the radius needed. So using the area= pi r squared from high school geometry, it doesn't come close to being able to reach where it's supposed to... lots of chunks of whatever you are trying to blend or turn into a smoothie in the bottom of it's huge container. Easier to mix powder in liquid in an old peanut butter jar. This is pretty much worthless.