Why is running making me fat?

April 15th, 2010  |  Published in Stumpblog  |  12 Comments

Most people overestimate how many calories they’ve burned during exercise, so they overindulge at the dinner table and pack on the pounds.

Full story in the Globe and Mail

The article fails to mention that certain types of activity — particularly endurance cardio — can upregulate appetite, making you hungrier. Yet many folks do this to lose fat. Irony!


  1. Siobhan says:

    April 16th, 2010at 11:12 am(#)

    I’d be interested in reading more about your take on this, especially since you have seen significant changes in your body mass (I’ve always been interested in your “success story” and what you did and how long it took you–I’m also interested in how you changed your relationship to food/nutrition). I bet other readers would, too.

  2. Shannon says:

    April 16th, 2010at 12:08 pm(#)

    What other types of activity are you referring to?

  3. Mistress Krista says:

    April 16th, 2010at 12:10 pm(#)

    Endurance cardio would be the big one for appetite stimulation. It varies from person to person, but generally the stimulation of catecholamines by intense exercise can result in appetite suppression.

  4. Mistress Krista says:

    April 16th, 2010at 12:15 pm(#)

    Siobhan: My take on this is pretty simple.

    1. We all bullshit ourselves. Humans are fantastic at self-delusion.
    2. Research shows that most of us eat more than we think, and we are active less than we think.
    3. You can’t just eat less OR exercise to lose fat; usually you need to do both.
    4. Exercise is not a “get out of jail free” card unless you’re swimming the English Channel every day or skiing to the North Pole. Or Michael Phelps. (And this freebie will run out for him in 20 years.)
    5. You have to be aware, conscious, and realistic about what you do, and what you put in your mouth.
    6. The details don’t matter as much as the big picture: Eat less, but not too much less. Eat real food. Move. Do the right things over and over.
    7. Care for your insides and your outsides will take care of themselves.

    These factors above are what will determine your rate of body change. You have to confront these in order to change your body. How much you’re willing to confront them determines your rate of change.

  5. Kat says:

    April 16th, 2010at 12:33 pm(#)

    Anecdotally, I completely concur that endurance cardio upregulates appetite (I don’t know anyone who’s completed marathon, half-IM, or IM training without packing on a few pounds).

    But what’s odd is that using some quick Pubmed searches, I’m having trouble finding any citations to back this up at an endocrinological level, and what I am finding is data suggesting the opposite. I’m just skimming the surface here, but look at http://www.ncbi.nlm.nih.gov/pubmed/18987287 and http://www.ncbi.nlm.nih.gov/pubmed/19247279 for starters. http://www.ncbi.nlm.nih.gov/pubmed/17462789 is a rat study, but is also interesting. Even in a couple studies finding an association between long-term running and increased ghrelin levels, reviewed in http://www.ncbi.nlm.nih.gov/pubmed/17259325 , there seems to be a confound with reproductive functionality: in amenhorreic athletes, ghrelin was way up compared with athletes with normal reproductive function (suggesting to me, at least, that this is a last-ditch effort by the pituitary to get people who are running themselves into starvation to put some calories into their faces). Furthermore, in a human study of treadmill running, ghrelin was not increased (http://www.ncbi.nlm.nih.gov/pubmed/20152871). Similarly, in endurance-trained animals, hepatic AGRP mRNA is way down and plasma levels of ghrelin are also down, although plasma levels of AGRP are up in these animals (http://www.ncbi.nlm.nih.gov/pubmed/19910650 and http://www.ncbi.nlm.nih.gov/pubmed/19632697).

    In fact, the only citation I found to back up an endocrinological basis for hyperphagia after exercise was a study looking at low-intensity circuit training (http://www.ncbi.nlm.nih.gov/pubmed/17368650). (Yet another argument against low-intensity “strength” training…)

    I’m wondering how much of the appetite upregulation that endurance athletes experience is due to actual homeostatic mechanisms and how much of it is due to some weird sort of social conditioning or some other psychological factor (the belief that you’ve done all this training, so you really MUST want to eat that cupcake or something, or a kind of “bargaining” with yourself that allows you to eat extra calories because you “virtuously” exercised). It’s kind of disturbing to find more evidence supporting how deeply out of touch most people in modern society have become with the actual needs and desires of their bodies, as opposed to what they believe they need and want.

  6. Simma says:

    April 16th, 2010at 10:49 pm(#)

    I find that weightlifting upregulates appetite tremendously–just not immediately after exercise. And my anecdotal and personal experience with it is that I tend to crave protein and fat more when weightlifting, whereas cardio (I haven’t done steady-state cardio in a while) made me want starch and sugar like crazy.

    I don’t know whether studies have been adequately done on this, since almost nobody studies the kind of weightlifting you advocate for here; almost all exercise research is done using some form of cardio or a very light weightlifting regime.

    Regardless, wouldn’t the bigger issue be the relationship between release of catabolic hormones vs. anabolic in different modes of exercise?

    I would think that another good reason why long distance runners gain fat is that they are using a mode of training which increases their production of cortisol over long periods of time, but which doesn’t reach intensity levels high enough to trigger enough production of HGH and testosterone to counteract cortisol’s muscle wasting effects. In fact, don’t a lot of studies show testosterone deficiency in endurance athletes? Essentially, long distance cardio is a muscle wasting activity. So decrease in lean mass + greater efficiency + a carb-centric diet culture = an extra thrifty metabolism primed to gain fat.

    I would guess that elite endurance athletes either have genetic idiosyncrasies which cause them to remain rail thin, or the sheer volume of work they put in (vs. your average person for whom long distance endurance racing is a hobby) keeps them that way. But for most of us, it’s hardly surprising that steady-state, long-duration cardio can and does make us gain weight.

  7. Shannon says:

    April 17th, 2010at 11:36 am(#)

    Siobhan’s comments remind me – where is the link you used to have to your weight-loss story? It had a before shot and maybe some afters as well. I also can’t find the collection of pics you took in December 2001 (I think). I didn’t know if you decided to take them down or they just got lost in the site redesign shuffle.

  8. Justin_P says:

    April 19th, 2010at 8:57 am(#)

    I think that people don’t keep in mind is that the body values fat tissue more than muscle if it perceives a condition where it thinks that food is scarce and staravtion may kick in.

  9. Emily says:

    April 20th, 2010at 8:26 am(#)

    Question about the end of the article:

    Why do women burn fewer calories than men whilst running at the same pace?

  10. Mistress Krista says:

    April 20th, 2010at 1:31 pm(#)

    Two main reasons: hormonal and lean mass. Men have a different hormonal environment than women; they carry more lean mass. Both of these things make men’s engines “rev” at a higher speed, metabolically. For example, if we have a 150 lb man and 150 lb woman, with average-lean body fat %, the 150 lb man will carry (let’s say) around 132 lb of lean mass, while the 150 lb will have 120. You could probably also work out some biomechanical equation around body density and work to move a certain pace. Women tend to be very “efficient”, metabolically speaking. They store and retain fat better, and their engine revs lower.

    On the other hand, “calories burned” is not always a useful way to understand fat loss. It’s not just an input-output system. It’s highly organized by our chemical environment, the nature of the foods we eat, our energy balance relative to activity, etc. Just sayin’.

  11. Simma says:

    April 21st, 2010at 2:37 am(#)


    High intensity short duration exercise is supposed to be muscle sparing. Steady state cardio is not.

    Studies show much greater fat loss using interval style training vs. steady state cardio.

  12. Emily says:

    May 7th, 2010at 9:33 am(#)

    Thanks Krista – that’s a more comprehensible (and interesting!) answer than the ‘because they’re smaller’ that I got from my work colleague!

Get "Fuck Calories"

Enter your information below and the magical gnomes that run Stumptuous will send you a copy of the "Fuck Calories" e-book for free!
Email Marketing by Javelin