First let's get our semantics straight. This list is about trends, not fads. The difference being that a fad is a phenomenon that blows up quickly, lasts only for a short time, then, fades away. A trend is something that gains momentum and can create long-term impact in the way people think or behave. In other words, a trend is a "movement."
As a fitness professional and weight lifting enthusiast, I often like to shake things up with a new and different form of exercise. For a change of pace, I have been experimenting with Tabata training. Of all the high intensity interval training options out there, Tabata meets my needs the best because I feel like I can do anything for 20 seconds!