This case is really simple and clear approach to self-experimentation by using weight information. But it has unique feature for he only focused on his weigh and energy status and also his goal was training himself not rather than accumulating the body data. The interesting part is that he used his mood, energy level which is very subjective to measure and use for self-tracking. But the thing is that he don’t need any accurate data. Paying attention to your body and teaching your body to be certain condition is his goal and it seems like he achieved what he wanted.
It is easy to think that objective, quantified metrics are always better than subjective metrics but with this case, we do have to consider what is the final goal of this self-experimentation and what is more time and effort efficient to end user.
In someone’s mind, there is hypothesis, then the first thing is to gather data as many as we can. Once you get the facts, then you can live by that facts. However, this experimentation is skip the stage of getting the fact and jump to the goal. Robin got to know the fact and taught his body by intuition, not with quantified data.