Comment by jeltz
3 years ago
While I agree with that excerice isn't a very efficient way to lose weight I think that you understate how many calories running burns.
When I run consistently I need to eat what feels like a lot more food to maintain my weight. Running burns about 700-800 kcal per hour for me (I have a quite small build) which ends up quite a bit over a week (I run 5-8 hours per week).
Think about it this way. The rate at which you burn calories is directly proportional to the rate at which you breathe out CO2 because that what happens with carbon you burn.
So if every day you train for an hour so that your breathing is 3 times faster, then you have additional two hours of burning in a day. 23 usual hours plus one worth 3. So you have 26 instead of 24 hours in a day.
It's way easier to put 15% less on your plate every day than to intensly train for an hour each day while keeping portions the same.
You're assuming that breathing rate is proportional to CO2 breathed out, which I doubt. I barely breath any faster while running than while just sitting here, much less than 3x.
It is directly proportional because of how lungs work. The percentage of CO2 in exhaled air is roughly the same regardless of how fast you are breathing (if you don't artificially accelerate your breathing beyond what your body dictates).
Lungs can't put in more CO2 in breathed out air.
If you breath only slightly faster when you are running than when you are sitting that must mean you ran quite a lot and optimized your stride so that you don't burn much more calories running than sitting.
But more likely explanation is that you are not aware how fast exactly you are breathing when sitting and running. Try to measure it. Also take into account that you might be taking shallower breaths when you are sitting.
Just blow up a balloon when you are sitting and when you are running with your normal exhaled breath for few seconds to test it.
Yes but in numbers it is way more. If I bike for an hour I burn 700-1000kcal . Thats not 15 but 50% of the dayli calorie intake… i am no expert btw. My understanding is that the problem is more that after 20 minuts of sport, at a certain heart rate, is starting to burn fat…but not body fat. More free floating fat. And it takes one hour or so to start burning bodymass. So the fuel for one hour sport is what I ate before and not my bodyfat. Another example. I do mountaineering, mostly 1 week walking in the alps for 10h a day. Thats around 4000kcal more burned a day. And there I see instant results with all my friends coming with me . They get thin very fast. Around 500g of body mass a day :)
> If I bike for an hour I burn 700-1000kcal . Thats not 15 but 50% of the dayli calorie intake…
That's estimated and probably impossible.
1000 kcal is 4184000 joules, divided by 3600 it gives you around 1100W
Human at rest burns about 100W. Pro-cyclist can do additional 400W. There's no way you can burn energy at the rate of 1.1kW consistently for an hour unless you literally set yourself on fire.
EDIT:
I was wrong.
Apparently 700kcal burned per hour of cycling is a pretty realistic number. https://www.welovecycling.com/wide/2020/05/14/how-to-convert...
Also resting kcal burn might be around 1800 per day. So 40% increase in of calories burned by hour of cycling per day every day is achievable.
The question is how can you breathe out additional ~10h of CO2 within an hour?
3 times deeper breathes 3 times faster? Because that carbon has to go somewhere.
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Also, you don’t absorb everything you eat. Actually, let me be clear: I have no evidence for this. But the fact that my weight is so consistent despite my radically inconsistent eating and exercising suggests to me that my body can regulate digestion. When I’m in a period when I’m overeating, my body just doesn’t absorb so much.
Again, more speculation, but i would imagine that metabolic disorders involve digestive regulation issues, not just lack of exercise and overeating.
You are arguing a different point. They argued that doing exercise burns more calories than sitting idle.
@1_player said: > Your body burns incredibly more energy just "being there" than you burn moving about.
I was objecting to the word "incredibly".
TEE is what the article discusses measuring, not the energy burned during the exercises but the total in the day. The data in the referenced studies indicate the body compensates for the calories burned running by cutting back in energy use elsewhere.
I have no clue how many calories running burns, but the act of moving around leaves you less time to eat :). Getting fat in the dark winters of Sweden is more likely for me, because I'm just bored and don't want to go outside as much so I sit inside and eat chocolate.
The problem is, it isn't efficient if you are overweight :)
When I was at my heaviest weight, I could only do a normal-speed walk, which burned relatively little calories.
At my lightest, I was also having to go out of my way to eat extra calories, as I was cycling so much, and a fast 90 minute cycle would leave me light-headed if I didn't eat some extra calories.
This is primary that thing where exercising makes you more fit and in the long term more active in general. Because what was previously tiring straining activity suddenly becomes pleasurable. And if you eventually manage to stumble upon activity you actually like, it is way easier to do it then to sit at home hungry, passive and obsessed about how miserable you feel (until said person will break and eat a candy or something similar).