I've been curious about this for a while. Seems like it is a lot of work but could be useful in small sustained bursts of effort (maybe 2 months) - much like diet logging. Will yield some insights and benefits and you don't have to keep it up forever.

Anyone have suggestions for software or other tools? The article explained motivations but was pretty light on the methods. To stretch the analogy above, is there a MyFitnessPal for this or do people's aims vary enough the everyone just rolls their own spreadsheets?