From Wired Magazine, in their style, just what needs to be said. Biofeedback isn't about brainwaves necessarily, it is about keeping track and the ability to review, notice, and than choose to alter patterns.
There is a vast universe of personal metrics to capture. Start with these:
height // weight // age // birth weight // birth length
body temperature // pulse // blood pressure // respiratory rate
visual acuity // auditory acuity
glucose level // blood-alcohol level // hemoglobin level // HDL level // LDL level // liver enzyme level
estrogen levels // menstrual cycle
testosterone levels // sperm count
caloric intake // hours of sleep // exercise duration // exercise intensity // lactate threshold // steps taken in day // mood // medication taken // hours worked // cigarettes smoked
and wait, there is more:
A piece of wisdom from Nike research:
"But that simple, dual-variable tracking can lead to novel insights, especially once you have so many people feeding in data: The most popular day for running is Sunday, and most Nike+ users tend to work out in the evening. After the holidays, there's a huge increase in the number of goals that runners set; this past January, they set 312 percent more goals than the month before.
"There's something even deeper. Nike has discovered that there's a magic number for a Nike+ user: five. If someone uploads only a couple of runs to the site, they might just be trying it out. But once they hit five runs, they're massively more likely to keep running and uploading data. At five runs, they've gotten hooked on what their data tells them about themselves."
But wait, there is still more:
This is why BeingSense is a wannabe: http://www.quantifiedself.com/
As soon as I saw the name of Kevin Kelly (Cool Tools and much more) starbursts appeared on the horizon. Worth the trip and happy to supply the introductory link. You're welcome.