I would say the reason you do not have an answer is because no-one understands your question.

The word "extract" usually means "remove from" so the picture I immediately have, is that you are removing their metabolism. Obviously that is not what you are asking.

What are you asking? I'm guessing you want to measure energy levels. Rewrite your question, explain it better and then someone will understand what you want to do.

And by the way, when any of you see spam like above, please report it. The sooner it is reported, the sooner it disappears and no-one gets scammed.