How does your body burn 2000 calories a day without any effort, but running a mile only burns 100 calories?


How does your body burn 2000 calories a day without any effort, but running a mile only burns 100 calories?

In: 7671

Half of your calories go to running your brain.

And your heart beats constantly, which is a lot of effort.

And your chest expands and contracts constantly so you breathe.

If your body stopped putting in effort you would die very quickly.

You use energy to breathe, to keep your heart beating, to maintain all your weight at 37°C, to keep your brain working. On top of all that energy expenditure, moving your body a mile is chump change.

Most of the calories burned are just maintaining body temperature, pumping blood, and breathing. That’s around 1300 calories per day on average. The rest of the daily average is your daily movement.

The reason running a mile is only 100 calories or so is because it is only 15-20 minutes of moving your weight along the ground, and human evolution made us remarkably efficient at it. You only burn slightly more running than walking because roughly the same amount of work is being done in a physics sense. Plus the more you run the more efficient your body gets.

Your bodily functions run 24 hours per day. Running for 24 hours ~~which is impossible as far as i know,~~ would be 9600 additional calories. So it’s not really a matter of how little calories you burn running, but more that it is just a small amount of time comparatively.

Edit – see below

Keeping all your muscles and organs running and alive takes a ton of energy, more than you’d think. And humans are adapted to be very efficient at running, taking less energy for a mile than you’d think.

For example, your brain itself burns 20% of the calories you eat. So with 2000/day that’s 400 cal just to keep your brain functioning for a day. Makes sense though, it’s constantly sending out nerve signals and processing data from thousands of sensors.

The 100 calories is for an average 150 lb person, and this is above your normal energy consumption.

If your assumption of 2000 calories a day (BMR) is correct, that’s what you burn just sitting around. So your normal sitting around self burns 83 calories an hour or 13.8 calories in ten minutes.

If you run (jog) a ten minute mile you’ve burned 100 calories above the normal 13.8 calories you would have burned on the couch….so that’s quite a bit more energy burned….a factor of 8.25 times more.

So it’s not really “only” 100 calories….it’s 8.25 your normal energy expenditure.