I've had the epiphany that my body is a living vessel of energy production (and consumption), just like all other energy sources and associated forms of consumption or re-allocation around me.

My body produces sometimes a huge amount of energy (in one form or another - kinetic, heat - even electrical), but it's not being put to use for other things a lot of the time and quite a bit of energy wastage is occurring.

Is there no significant consequence to how we use our bodies' own generated energy - from a resources sustainability point of view - or are there considerations one can put into use in terms of harnessing one's body energy for external power consumption purposes?

It is of course healthy for our own bodies, to expend energy (i.e. to exercise), and no doubt more sustainable to use our own energy to power production of other things like transport (in the way of riding a bike instead of burning fuel, so long as what we ate was more sustainable to produce than the fuel we would consume in the automobile).

But what other ways can one use one's own body energy wisely, and in general what principles / themes can one explore to put it into practice?

Is there even some advantage in being mindful of not taking in too much energy (coming into your body) in the first place? (I.e., not consuming too much biomass resource in the first place?) And to extend that, maybe even more mindful diet and lifestyle (eating more efficiently energy absorption-wise, i.e. having a smart diet for better nutrient, protein and carbohydrate absorption rates, as well as getting good sleep and probably better-balanced exercise), is a relevant factor here? (A poor diet and lifestyle meaning you are a poorer - i.e. less efficient - medium of energy production/consumption?)

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    I suspect one of the biggest gains from eating an optimal diet (whatever that is... there's so much conflicting info out there!) and getting optimal exercise would be that you'd enormously reduce the environmental cost of the healthcare industry. Aug 14, 2014 at 7:50
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    @H I That's right, I know that for a fact already. Being healthier means less strain on the environment simply by not consuming as many (or any) pharmaceutical drugs, receiving complicated treatment, or surgery, meaning not only not consuming the resources put into and as a part of such treatment, but also less trips to the doctor/hospital as well. But I'm talking more specifically about body energy use, which I think is a highly interesting idea: energy sustainability, in relation to the environment. How can I put more of my body energy to use for sustainable energy consumption?
    – user487
    Aug 14, 2014 at 23:12
  • Rather than a "smaller" diet, a meat-free one is much less resource-intensive, but it's likely to be volumetrically larger. Similarly a healthy diet is likely to be more resource-intensive to process and transport because it's got less fat and sugar (= lower energy density). As well, if you eat healthy food you're likely to live longer and so consume more resources.
    – Móż
    Aug 15, 2014 at 0:57
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    The trouble is that your question is extremely broad and general, so it's not answerable. Right at the start: are you trying to minimise your energy intake, or maximise the utility of your energy output?
    – Móż
    Aug 15, 2014 at 3:18
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    From a reusing/saving energy perspective; the only thing that comes to mind is crawling together in bed or on the couch with your partners, kids or other housemates to keep warm in the winter so you need less energy for heating.
    – THelper
    Aug 15, 2014 at 11:50

6 Answers 6


"Is there no significant consequence to how we use our bodies' own generated energy - from a resources sustainability point of view - or are there considerations one can put into use in terms of harnessing one's body energy for external power consumption purposes?"

I feel like this one question you asked fairly neatly sums up your entire overall question. So I am going to answer this in terms of body inputs and outputs, ie, what you eat and how you burn your calories.

As far as eating goes, eating lower down on the food chain is better for the environment. (Full disclosure: I'm an omnivore.) So if you want to do the best thing you can for the environment as far as inputs (what you're eating) and outputs (how you exercise), I'll take this to the logical extreme and explain how you can do this.

1) Go vegan. Eating meat & dairy is pretty bad for the environment. People talk about CO2 emissions a lot, and methane emissions not nearly as often. Cows emit a large quantity of methane - cow farts, and methane is orders of magnitude worse for the environment than CO2 as far as a greenhouse gas.

2) Ride a bicycle or take the bus when the distance is too long for bike travel to be practical. While walking is great for your body and the environment, from a calorie expenditure perspective, you will get a lot more out of your energy by biking places instead of walking. But there's a cost to this: avid bicyclists tend to burn a lot more calories than the rest of us. You'll need to eat 3,000 - 4,000 calories a day to maintain your body weight if you become a serious bicyclist. See also point one for reducing the impact of this decision. (Alternatively, eating lower on the food chain is also much better for the environment in general. Fried grasshoppers, anyone?)

3) Ditch your car. If anything, this is a harder decision to make than one or two, potentially. I don't drive, and it impacts the whole way I live. But on the whole, I find it to be worthwhile.

Here are the benefits to not driving:

a) If you aren't sitting around reading all the time, you'll never need to go to the gym. I walk everywhere I can, and when this isn't possible, I take the bus. It means arranging my life somewhat around the bus schedule (occasionally) or trying to live in a city that's walking friendly so you don't have to worry about buses. Or, better yet, living a city like Davis, CA, that has Class I bike paths throughout the city so you can bike all over the place and not worry about getting hit by a car.

b) You'll save hundreds of thousands of dollars over the course of your life in gas money, car insurance, car payments, etc that you won't have to pay. If you invest the money well you save by not owning a car, you could easily retire a decade earlier than the standard retirement age, if not earlier.

c) Never needing to worry about the price of gasoline. This one's really a nice subset of point b, but it's a fun addition for me personally.

The downsides are probably obvious so I won't go into them here.


To answer this portion of your question:

"But what other ways can one use one's own body energy wisely, and in general what principles / themes can one explore to put it into practice? "

You made mention of using your body for transportation but you can go beyond just transportation. You can use peddle power or a rowing machine to power your cell phone, to operate a washing machine, to charge batteries. The Solar Living Institute in Hopland, CA is one place I've seen stationary bikes set up to charge batteries. Just a couple of examples of using your "own body as an energy source for greater environmental sustainability".

Use your creative brain energy to think of more!

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    Not “peddle power” but “pedal power”!
    – PJTraill
    Feb 26, 2020 at 11:27

I see the human body as an energy consumer rather than producer. I would agree that controlling your diet (quantity and quality) will have energy benefit on the overall system by making him run smoothly and more efficiently, so that will be a definite gain of energy, but not a way to harvest the body energy.

To simply exercise is I think a waste of energy, yes it helps to be fit as said above but you are actually burning energy for nothing (not to mention those who run on a treadmill...). If, like me, you have a lifestyle that is simply not physical enough to ensure fitness by itself, I would rather here advocate for the usage of machine that would actually output electricity, you basically burn your extra calories and transform them in electricity (rather than just heat). You can as well equip yourself with smart appliances such as hand crank flashlights rather than battery operated ones,...

Except that, I see only one thing, it would be to put the body heat at work. I did not see many successful work on that so far, but that is, in my mind, the only interesting direction, just because the heat is the energy we lose, the one that is so far just burned away. In that regard, staying warm would then be a way to limit our energy consumption by not burning to much. Almost all other energy consumption is already put at use for transportation, thinking, working, ...


Foregon, I don't know where you are, but where I live, conserving body heat (especially at night) can be a big contributor towards reduced fossil fuel consumption. Many homes are heated with fossil fuels (or with wood that might otherwise be left standing). Given that we have to eat and produce ~100 W waste heat anyway, why not use that heat to remain comfortable during the heating season, instead of heating the whole house?

In a word, my answer is: Blankets.

I'm sorry if that sounds overly North American. :)

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    If your living space is airtight and insulated enough, "waste" body heat can make a significant contribution to space heating - e.g. see the passivhaus specs
    – aucuparia
    Oct 29, 2014 at 12:27

My body produces sometimes a huge amount of energy

False. Even a very active person typically doesn't need to consume more than 3,000 kcal a day. This is equivalent to about 3.5 kilowatt hours. This is equivalent to the average solar insolation over about 4 square feet (not considering weather), or 1/10th a gallon of gasoline. It's not a particularly significant amount; the US per capita daily electricity use is over 10 times higher.

But still, how can that energy be used effectively? Looking at transport, running takes somewhere around 100 calories per mile. This comes out to 285 MPGe. Biking takes somewhere roughly around half that, so 570 MPGe.

Whether either of those is "green" and comes out ahead of hopping in your car depends on the input of those calories. There are some fairly rough estimates of input energy efficiency here that range from 4% efficiency for beef to 102% efficiency for corn.

  • It's not as simplistic as just calories - many hormones provide energy to the body (some of which, like serotonin, are simply provided from the unlimited source of the sun), and if you run out of calories you burn fat (and also even if you still have calories it doesn't mean you have the energy to burn the rest, again, often regulated by energy-giving or draining hormones) so it can't just be calorie input/output in the equations - but I have appreciated the thoughts, and have upvoted. Thanks
    – user487
    Sep 9, 2014 at 0:59
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    Hormones regulate energy usage in the body/cells; they aren't an actual energy source (and if they were, their intake would be counted at a calorie source). Additionally, hormones aren't provided by sunlight; some are generated in response to sunlight, but we don't meaningfully absorb any energy from sunlight beyond any warmth it provides. Although it's true that for any given day, it's much more complex than simple calories in/out, all of the energy you expend is derived from calories you consumed and over the long term, calorie input and output must balance.
    – Zhentar
    Sep 10, 2014 at 16:41
  • “Huge” is an exaggeration, but “significant” would be perfectly reasonable, after all US consumption is way above sustainable, and a tenth of that is worth using well. And since they said “sometimes”, they may be referring to peak power, which is far higher. Wikipedia gives 80W basal rate, 150W for an average fit person for an hour, 400W for a top cyclist for an hour (1kW in short bursts): plenty for some lighting and a laptop, too little for cooking.
    – PJTraill
    Feb 26, 2020 at 11:49

I can't remember the source, but some folks in Germany are making porn and using the proceeds to save the rainforest. Sooooo....,

also, in okanawa, they practice hara hachi bu, which means only eating til you are 80% full, and they are very productive and really old(and are therefore using too many resources?)

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