Metabolic and HIIT workouts continue to be effective media marketing. But what does this even mean? 

Nothing. These words mean NOTHING when it comes to workouts and fitness. 

Don't buy into the hype. People are still doing 'strength' workouts and 'cardio' workouts. This bullshit is JUST as ridiculous as the rest. 

There are no 'metabolic' workouts. There are no 'cardio' workouts. 

Human bodies JUST DON'T WORK LIKE THAT. 

And yes. It is important that you understand why.