It seems to me that he is leaving out a discussion of slow-twitch and fast-twitch muscles. Slow-twitch muscles are used in maintaining posture and light activi

It seems to me that he is leaving out a discussion of slow-twitch and fast-twitch muscles. Slow-twitch muscles are used in maintaining posture and light activity and burn primarily fat. Fast-twitch muscles are used for strength and burn primarily glucose. Hard exercise like he suggests would use mostly glucose. Walking slowly while working 8 hrs a day (treadmill desk) would presumably use more fat. It would be interesting to see if that is actually the case (within a 95% confidence interval, of course ;) )