Which says it goes up by 50%, i.e. an extra 125 calories per hour. He says "But you do not engage that long in such an activity" - maybe he doesn't. But I think most of the people here do.
“There are good, sophisticated studies that show that concentrated mental activity, like doing a difficult multiplication problem in your head, increases the glucose uptake to the brain,” he said. By how many calories? Less than, say, 20 calories of the 300, he estimated."
If it's an increase of 20 calories, then why is the total still 300?
Maybe I'm fooling myself, but I definitely notice/perceive the need for glucose after extended concentration. Whether from a longer respite and a good meal, or from a modest intake of something like soda. With the latter, though, it is difficult to keep from overindulging and inducing a sugar buzz/crash cycle.
Yeah, I agree. When I took long tests like the SAT or college final exams, I definitely noticed the drain. I needed some sugary drink/candy (or just beer) afterward, for sure.
In a way, it depends on how we define mental effort. If you concentrate on raising your heart and breathing rates - which are physical, but then so in a sense is mental effort - you can significantly affect calorie burn.
Right, and if you decide to run a marathon or become an Olympic athlete, that mental effort is going to burn even more calories. So I think it's clear that they're talking about calories burned by the mental activity, not calories burned by physical activity that was the result of mental activity.
I don't think that's what he meant. There is some evidence that with training some people can raise their heart rate or body temperature purely by thinking about it.
I had one girlfriend who became like a furnace when she slept. She slept with no covers with the window open in January in Ohio. I had to strip down to just one sheet. Literally, it was like sleeping next to a space heater. So it is possible for the body to increase its metabolic rate.
For the purposes of temperature control in places with extremely tight environmental requirements, the modelling assumption is that a human being gives off the same amount of thermal energy as a standard 100-watt incandescent lightbulb. When you check into the clean room, you turn off your bulb. When you leave you turn it back on. The bulbs also serve as a handy way to tell who is in the lab that day :)
I didn't realize that, and while it's informative and interesting, that doesn't change the issue: the article was talking about the extra calorie consumption from the mental process, not the extra calorie consumption caused by a mental process that leads to raising one's pulse, flexing one's abs, moving one's eyes, typing a comment, or swimming a lap.
Which says it goes up by 50%, i.e. an extra 125 calories per hour. He says "But you do not engage that long in such an activity" - maybe he doesn't. But I think most of the people here do.