Their procedure seemed a little lacking too. They measured jogging on a treadmill in the lab, then fitted them with 'unobtrusive armband' monitors. Does that measure the same thing as the lab equipment? Why not just use the armbands when on the treadmill, to get a comparable measurement?

Also, people doing Anything while others are watching, do it more deliberately than when private. So they only have conclusions about the activity level when wearing an armband, and while planning what to write in your journal afterward.