Mental exertion and energy

  • Hello all! I've been reading a bit more frequently, posting a bit more frequently, and gradually getting myself back into the groove of being conscious about my food.

    A few weeks ago I had a bit of a rant/meltdown about how my schedule seemed to be doing its damndest to enable me to eat whatever I liked. I love my work, but I don't love how much it exhausts me, and I definitely don't love how I reach for food to help me relax after a long day.

    So I'm trying to keep a careful eye on things, especially situations which tire me out, and how I deal with that.

    But I'm wondering to myself now: you know how you get those calculators which tell you, based on your weight/height/whatever, how many calories you burn doing all sorts of various activities? Like this one for example.

    I remember when I first saw these - I always looked up 'reading' because that was what I seemed to do the most of.

    How many calories do we burn by mental effort? By studying, preparing lessons, marking (UGH, bane of my life), writing research papers? How much energy does the brain need to function this intensively? All this must consume something because just as I can't exercise at a certain level for more than, say, an hour before I need a break, I can't sit and mark assignments for more than 40 minutes without getting up, walking around, and letting my brain do...well, nothing...for a few minutes.

    I don't want to suggest that people can sit and think very hard and call this an efficient calorie-burning activity ( ) - I think most people doing lots of 'intellectual' stuff will testify that the switch to physical exercise is sometimes really needed after a day in the office! But can we take intellectual effort into account when determining our calorie level? I mean, I know I'm not eating enough when, after an hour's "thinking" all I'm capable of is lying down and sleeping for a couple of hours

    What do you folks think?
  • http://www.bodyrecomposition.com/res...ch-review.html

    Read that. In short, seated knowledge-based work such as studying/thinking/writing and so on uses approximately the same number of calories as if you were sleeping.
  • Quote: I mean, I know I'm not eating enough when, after an hour's "thinking" all I'm capable of is lying down and sleeping for a couple of hours

    What do you folks think?
    I think you get an A for effort ... errr ... wishful thinking.
  • Laughing at me doesn't explain why after working for half an hour I have to nap. Uh, happy I've managed to make people laugh though, I suppose. It was just a question.
  • I didn't mean to offend! Sorry. I really didn't think you were totally serious that you couldn't do mental work for more than 40 minutes because you weren't eating enough. I really thought you were being a little tongue-in-cheek, and I thought I was laughing *with* you.

    I don't know why, but it's not because you're not eating enough, unless you're *really* not eating enough (starving). I think you just need a mental break. I can't exercise endlessly, but it's not because I'm not eating enough. It's because there's a limit to my physical fitness. And I think in general, the body and mind need to change paces from time to time.
  • I've wondered about this myself from time to time. I used to work in a call center doing credit card collections. I sat for 8 hours a day, in the same place, and it was the most stressful job I've ever had. There was nothing physical about this job at all except the five minute walk to and from the parking lot, but at the end of the day, I was exhausted. Not just tired of work, or getting screamed/cursed at all day (which was the norm for 90% of my calls), but completely out of energy. I would want to go home and lay on the couch until it was time to go to bed. I often felt the same way while I was working on my Bachelor's degree. It required me to be at the computer all day or night (most of my classes were online). At the end of a long day of classes, I would be exhausted. Before all of this, I worked in childcare where I rarely sat down at all. I was more energized when I was done working at the day care center than I ever was working a desk job or taking classes.

    I'm not saying that extreme mental stimulation should replace physical activity, but I really find it hard to believe that it uses the same level of energy as sleeping.
  • Quote: I'm not saying that extreme mental stimulation should replace physical activity, but I really find it hard to believe that it uses the same level of energy as sleeping.
    I'd agree with that. I remember in college candy and coffee drinks being downed in large volumes to deal with studying. Seems to me energy is being expended (electrical activity). The body must be reacting too, muscles tensing and who knows what. Would have to be more than when just asleep and the body is relaxed and the brain has little stimulus (as least from what I know!)

    I tend to reach for food after a long, tiring day too, when probably what I really want is to decompress and relax. it's a hard knee jerk reaction for me to get rid of.

    Plus, there's one day of the week I don't make it home until around 7:30 or so for dinner. For years we ate at 5 (I know some would consider that very early, ha). I have this mental thing about waiting that long to eat, I feel like I should have something, when in reality, it isn't that much of a hardship to hold out until then. It's more mental than physical, or hunger level.