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Discussion Starter · #1 ·
This may be the wrong forum for this question but I'll ask anyway.

How does a cyclist riding his bike compare, fuel consumption wise, with other forms of mobility? I mean, how many calories are there in a gallon of gas and how many calories does it take for an average cyclist to go a mile?

I was kinda amazed when I looked, one day, at my Garmin Edge calorie counter function after a 90 mile 7000' climbing day and saw something like 3500 calories..or something. I could probably sit and eat that at one semi-normal meal.(I may have, after that ride) In a vehicle, I'd likely burn up 5-6 gallons of gasoline to go that far...

If I worked ,say 20 miles away, and commuted each day would I be able to do the trip more 'effectively' on my bike or in a Prius?...Now I know this is dumb to ask..I've always ridden my bike whenever I have the option, because I LIKE riding and it makes me feel great...but I am still kinda curious about the numbers...

Don Hanson
 

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Interesting topic.
Just to be clear though we're talking purely about fuel consumption (food for us, petrol/diesel for cars) and not about environmental impact right? If the latter then we need to start getting into all sorts of stuff like how the food was transported or grown etc.

I did read an article once that talked about the efficiency of the human body and how coupled with a bicycle it was far more efficient than any motor engine. Wonder if I can dig that up.

Also interesting to think about the monetary costs involved. Speaking just in terms of fuel that 90miles cost you about a typical days worth of food (3500 calories). How much would it cost to drive a big car the same distance? What about a small one? or a motor bike? or a Prius? or even a fully electric car like a Tesla.
 

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I have a Prius. 50 Mile round trip to work uses about 1 gallon of fuel or around $2.00. When I bike round trip I eat a lot more additional food than that $2.00.

Makes me think driving may be more environmentally friendly than biking if I do not include the initial environmental cost of manufacturing the vehicle.
 

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Now imagine how many calories your ride would have burned if your bike weighed 2500 pounds. If you want to be able to compare the two then the work effort required must be similar.
 

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good article:

(quoted) "It turns out that "biological engines" -- which is what the muscles in your body are -- are pretty amazing in terms of efficiency. To find out how efficient, let's look at how many calories a person burns while riding a bicycle.
If you look at a page like this calorie chart, you will find that a person riding a bicycle at 15 miles per hour (24 km per hour) burns 0.049 calories per pound per minute. So a 175-pound (77-kg) person burns 515 calories in an hour, or about 34 calories per mile (about 21 calories per km).

A gallon of gasoline (about 4 liters) contains about 31,000 calories. If a person could drink gasoline, then a person could ride about 912 miles on a gallon of gas (about 360 km per liter). Considering that a normal car gets about 30 miles per gallon, that's pretty impressive!

To be fair, keep in mind that a car generally weighs a ton or more, while a bicycle weighs only 30 pounds. Cars also travel a lot faster than 15 mph. But it is still an interesting comparison. Note also that people cannot drink gasoline. However, people can drink vegetable oil, which contains nearly the same number of calories per gallon (if you look at How Fats Work you can see that fat contains long hydrogen/carbon chains just like gasoline does).

The people riding in a race like the Tour de France are riding more like 25 mph. Because air resistance rises very quickly with speed, they are burning about three times more calories -- something like 100 calories per mile. In a 100-mile stage of the tour, a racer might burn something like 8,000 to 10,000 calories in one day! So they are getting only about 300 miles per gallon. The only way to replace those calories is to eat a lot of food (see How Dieting Works for details)."

http://auto.howstuffworks.com/question527.htm

That pretty much sums it up for me.
 

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I really fit world-class endurance athlete, going flat out (e.g. a time trial) can burn about 1500kcal in an hour. Obviously, that is not sustainable for longer durations or doable by less fit persons.
 

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pennstater said:
Makes me think driving may be more environmentally friendly than biking if I do not include the initial environmental cost of manufacturing the vehicle.
We can grow more food and it can be done sustainably (although most likely the food you ate was not), once the gas is used, for our intents and purposes it's gone for good.
 

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Uhhhhh.........The amount of calories burned by a person is not only very subjective as a topic in itself, but it varies greatly from person to person. For instance, I rode just 32 miles last night (albeit it was a fairly intense effort) and my Garmin Edge said I burned almost 2500 calories. This is obviously very different from your 3500 calories for a 90 mile ride. I'd burn 7000-8000 in 90 miles. Calories burned depends on you weight, age, heart rate throughout the ride (which is implied level of effort) and overall conditioning level. I'm 6'1", 210lbs and my average HR last night was 154. Based on your calories burned number, I'd guess you at 5'6", 150lbs and in pretty good condition (at least much better than average condition). I bet your avg HR was somewhere around 140 for your ride. It's comparing apples and oranges....too many variables.

IMHO, it's nearly impossible to compare HR's, and calories burned from person to person....let alone compare to it to the energy efficiency of a motorized vehicle.
 

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Discussion Starter · #9 ·
Well, how about asking something like: "How many ears of corn would it take to make up enough fuel to go, say, 100 kilometers, and How may ears to supply enough calories for a cyclist to go the same distance" Or, we could make that Soy beans and diesel.

It's obvious that you include the process of making the vehicle, (taking it from raw materials to drivers butt) then the bike would be a waay more effective use of resources. We all know that petroleum products from the ground are cheap right now but that soon enough, that stuff will be gone (except for those with lots of cash) but how about a comparo- Calorie for Calorie between motor vehicle and bicycle..You know, which is better, "A couple-a Big Macs and the bike, or 15 gallons of Premium and the Humvee"?

Don Hanson
 

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jtsk said:
Uhhhhh.........The amount of calories burned by a person is not only very subjective as a topic in itself, but it varies greatly from person to person. For instance, I rode just 32 miles last night (albeit it was a fairly intense effort) and my Garmin Edge said I burned almost 2500 calories. This is obviously very different from your 3500 calories for a 90 mile ride. I'd burn 7000-8000 in 90 miles. Calories burned depends on you weight, age, heart rate throughout the ride (which is implied level of effort) and overall conditioning level. I'm 6'1", 210lbs and my average HR last night was 154. Based on your calories burned number, I'd guess you at 5'6", 150lbs and in pretty good condition (at least much better than average condition). I bet your avg HR was somewhere around 140 for your ride. It's comparing apples and oranges....too many variables.

IMHO, it's nearly impossible to compare HR's, and calories burned from person to person....let alone compare to it to the energy efficiency of a motorized vehicle.
It is fairly trivial to calculate calories burned with indirect or direct calorimetry, or to estimate the calories burned if you have a powermeter (since riders don't differ very much in their efficiency). On the other hand, the further you're from actually measuring heat, lung gasses or work the more unreliable the estimate will become.

Again, we know roughly the upper limit of human performance and the fittest folks on the planet can work at a rate that burns about 1500kcal in one hour of an all-out effort. This at a minimum gives a person using a device like the Garmin or a treadmill at the gym an idea if the number it spits out is at all realistic.
 

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Dwayne Barry said:
We can grow more food and it can be done sustainably (although most likely the food you ate was not), once the gas is used, for our intents and purposes it's gone for good.
Yes, and the vehicle could be fueled by hydrogen generated from solar or wind power and water. But it isn't. Today's agriculture and distribution network is energy intensive. I can't personally attest to the veracity of the following statement but it is clear that though the human body is extremely efficient, food production certainly is not:

Agriculture’s Excessive Energy Consumption
Ironically, industrial agriculture is contributing to its own future instability with high rates of fossil fuel consumption. Twenty percent of the fossil fuel used in the United States goes toward food production. The U.S. food system includes agricultural production, the processes involved in growing and harvesting food crops and livestock, as well as the post-agricultural processes of transporting, packaging, and storing food. This inefficient system uses 10 nonrenewable fossil fuel calories to produce only one food calorie, and spends a total of 10,551 quadrillion joules of energy each year, which is roughly the same amount used annually by all of France. Only one-fifth of this energy is used in agricultural production. The rest is expended moving, processing, packaging, selling, and storing food after it leaves the farm.


Therefore, I must compare the impact of today's driving (almost anyone can own a Prius) with today's mass food production and distribution. So, I MAY be doing more environmental harm biking than driving.

Just saying the answer as to which is more damaging is not automatic.
 

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pennstater said:
Yes, and the vehicle could be fueled by hydrogen generated from solar or wind power and water. But it isn't. Today's agriculture and distribution network is energy intensive. I can't personally attest to the veracity of the following statement but it is clear that though the human body is extremely efficient, food production certainly is not:

Agriculture’s Excessive Energy Consumption
Ironically, industrial agriculture is contributing to its own future instability with high rates of fossil fuel consumption. Twenty percent of the fossil fuel used in the United States goes toward food production. The U.S. food system includes agricultural production, the processes involved in growing and harvesting food crops and livestock, as well as the post-agricultural processes of transporting, packaging, and storing food. This inefficient system uses 10 nonrenewable fossil fuel calories to produce only one food calorie, and spends a total of 10,551 quadrillion joules of energy each year, which is roughly the same amount used annually by all of France. Only one-fifth of this energy is used in agricultural production. The rest is expended moving, processing, packaging, selling, and storing food after it leaves the farm.


Therefore, I must compare the impact of today's driving (almost anyone can own a Prius) with today's mass food production and distribution. So, I MAY be doing more environmental harm biking than driving.

Just saying the answer as to which is more damaging is not automatic.
You could also consider growing/raising a substantial portion of your own food, or short of that, buying it from local producers.
 

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Discussion Starter · #13 ·
Flyboy 50 'gets it'. That is the kinda post I was looking for.

I don't have that Garmin file right here, but those numbers (in the Original Post) are for a Masters 60+ racer, very fit, going up from 600' elevation to 4000' on half the ride and down to 600' again, with some intermediate up and flat. 165lbs average HR at about 160, so fairly intense effort, but not race pace.

Geeze, If I could only drink gasoline, I might put out some big Horsepower...

Don Hanson
 

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I think the answer is pretty automatic.

If you ride your bike to work you:

Eat breakfast
Ride

If you drive a gasoline/battery powered vehicle to work you:

Eat breakfast
Consume gasoline
Consume electricity

You logic about the production of food only works if you don't eat. Otherwise, you're contributing to environmental damage in precisely the same way as a cyclist. I eat the same breakfast if I drive or if I ride 25 miles, don't you?

When you additionally throw in the environmental impact of the pollutants your hybrid is sending out the tailpipe, you no longer have even a reasonable comparison to a bicycle.

In terms of environmental damage due to production of the vehicle, might be a wash but I doubt it. Toyota's factories are far larger, consume more electricity, use much vaster quanities of dangerous pollutants than any bike manufacturing plant.

I don't think the comparison is even remotely close.
 

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Someone once did a trip and wrote about it. His goal was to ride as far as he could on the equivalent of 1 gallon of gasoline.

1 gallon of gasoline is 30,000calories. He made it 650mi. Not quite infinity, but awesome, nonetheless.
 

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terry b said:
I think the answer is pretty automatic.

You logic about the production of food only works if you don't eat. Otherwise, you're contributing to environmental damage in precisely the same way as a cyclist. I eat the same breakfast if I drive or if I ride 25 miles, don't you?
If you're burning more calories, you have to eat more or you'll lose weight. If you're burning fewer calories, you have to eat less or you'll gain weight. There's no free lunch either way.

(amusingly, while the bicyclist certainly uses less energy than the driver, it's easy for his fuel to _cost_ more than the drivers.)
 

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russotto said:
(amusingly, while the bicyclist certainly uses less energy than the driver, it's easy for his fuel to _cost_ more than the drivers.)
And when you think about our food is really inexpensive today because the ridicously low cost of energy allows for cheap production of fertilizers, and low operating costs of harvesting & transportation machinery...and governement farm welfare (i.e., subsidies), our food "should" cost a lot more than it does.
 

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Gnarly 928 said:
It's obvious that you include the process of making the vehicle, (taking it from raw materials to drivers butt) then the bike would be a waay more effective use of resources. We all know that petroleum products from the ground are cheap right now but that soon enough, that stuff will be gone (except for those with lots of cash) but how about a comparo- Calorie for Calorie between motor vehicle and bicycle..You know, which is better, "A couple-a Big Macs and the bike, or 15 gallons of Premium and the Humvee"?

Don Hanson

Manufacturing a bike and its parts (and petroleum-based lubricants) also requires energy and transport. Clearly a heck of a lot less than a car, though. But the manufacturing of a bike does count for something.
 

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Yeah, food costs more to produce than gasoline or diesel, but a human on a 20-30 lb bike (the most efficient means of locomotion in the world, IIRC) is so tremendously more efficient than 2000 lbs of rolling steel, glass and plastic being powered by a 10% efficient intrernal combustion engine, that it's not even a close comparison.

Like TerryB, I only consume more food if I'm going out for a 50+ mile ride. For my 22 mile daily commute, I consume no additional food.

Oh, and if we're going to the extremes, how about the fact that I don't have to drive to the hospital in an ambulance and use all those meds and hospital resouces if I don't have a heart attack because I never got any exercise?
 

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Gnarly 928 said:
This may be the wrong forum for this question but I'll ask anyway.

How does a cyclist riding his bike compare, fuel consumption wise, with other forms of mobility? I mean, how many calories are there in a gallon of gas and how many calories does it take for an average cyclist to go a mile?

I was kinda amazed when I looked, one day, at my Garmin Edge calorie counter function after a 90 mile 7000' climbing day and saw something like 3500 calories..or something. I could probably sit and eat that at one semi-normal meal.(I may have, after that ride) In a vehicle, I'd likely burn up 5-6 gallons of gasoline to go that far...

If I worked ,say 20 miles away, and commuted each day would I be able to do the trip more 'effectively' on my bike or in a Prius?...Now I know this is dumb to ask..I've always ridden my bike whenever I have the option, because I LIKE riding and it makes me feel great...but I am still kinda curious about the numbers...

Don Hanson

Do a search on Google (or whatever favorite search engine you use). There are many. here is an example:
http://www.bmi-calculator.net/bmr-calculator/

Next, plug all the numbers in and see what it takes to operate your body for a day (i.e., the number of calories). This number is probably pretty accurate (or average your results among many of these such sites) for a base calculation provided you are perfectly motionless for the entire day. The next step is where it gets tricky because lots of variables get introduced.

The next step is to add on the energy expenditure and see what the calorie burning is from that. And, what you eat.

Nutritionists use a device called a bomb calorimeter to see what the caloric value of food is. In this device they add a certain amount of burnable stuff (a known amount) along with the food and burn it up. The resultant energy released (minus the burnable stuff) yield the amount of calories.

You can't put your body in the same kind of device because you'll suffer a different kind of burn-out. (sorry, couldn't resist). Instead, there is a device where they enclose a person is a very teeny room and measure all input (i.e., air) and output (heat, sweat, etc.) Somehow all this data is used to come up with a pretty accurate calorie expenditure calculation.

So, what does that mean for you?

Here is something that someone put together that is interesting:

http://www.exploratorium.edu/cycling/aerodynamics1.html

But, if you go back to your physics classes (the memory of those is long gone for me) you can see what energy was spent doing a particular amount of work (like calculate the number of watts to climb up a hill.) How this relates to calories consumed is a little more complicated.

If you want a true measurement you could probably get one of those BodyBugg things they use on The Biggest Loser show. It does the same kind of thing - enter weight, age, and it takes heart rate and some other data to calculate a perceived amount of calorie burn. Add to this what you eat in a day and you'll get a pretty good picture of inputs and outputs.

Bottom line is that it is not too complicated to measure how many calories are used, you just need the proper equipment.
 
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