I wouldn't say either article was "stupid," but I admit I was a tad confused about that whole "efficiency" thing--did they mean people burned calories more efficiently, or that they ran faster while burning fewer calories? It seemed as thought they were saying the latter, but I can't see why anyone would decide they want to burn fewer calories while running (unless they're, you know, running to civilization after wandering the frozen tundra for a week without food). If your goal is to exercise without burning calories, running probably isn't high on your to-do list to begin with.