calories burned while riding a bike - what is the correct number?

Joe said:

I've been dieting and I'm curious to see how many calories riding my
bike an hour per day through a wooded trail burns. I bike at a
moderate pace between 10-15 mph and if I do a calculation on this site
I get numbers in the 700 range.

http://dftools.ivillage.com/healthtools/calc_cb.cfm

My wife seems to think that number is way too high since she says
riding the exercise bike at the gym for one hour burns 1/2 that. I'm
trying to count my calories burned per day and I'd really like to get
an accurate number to put on my chart. Which would be correct?

The correct number is 99 billion.

J.

Joe wrote:
:: I've been dieting and I'm curious to see how many calories riding my
:: bike an hour per day through a wooded trail burns. I bike at a
:: moderate pace between 10-15 mph and if I do a calculation on this
:: site I get numbers in the 700 range.
::
:: http://dftools.ivillage.com/healthtools/calc_cb.cfm
::
:: My wife seems to think that number is way too high since she says
:: riding the exercise bike at the gym for one hour burns 1/2 that. I'm
:: trying to count my calories burned per day and I'd really like to get
:: an accurate number to put on my chart. Which would be correct?

I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400 kcals. 15
miles = 600 kcals.
20 miles = 800 kcals. Note, riding faster means you go more miles in an
hour, so that's how you burn more calories. For the most part, though,
you're doing the same about of work regardless of speed. Hence, the energy
used should really have little (to the first order) to do with speed.

I think the numbers at the site are too high.

"Roger Zoul" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Joe wrote:
:: I've been dieting and I'm curious to see how many calories riding my
:: bike an hour per day through a wooded trail burns. I bike at a
:: moderate pace between 10-15 mph and if I do a calculation on this
:: site I get numbers in the 700 range.
::
:: http://dftools.ivillage.com/healthtools/calc_cb.cfm
::
:: My wife seems to think that number is way too high since she says
:: riding the exercise bike at the gym for one hour burns 1/2 that. I'm
:: trying to count my calories burned per day and I'd really like to get
:: an accurate number to put on my chart. Which would be correct?

I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400 kcals.
15 miles = 600 kcals.

I'll second the 40 cal per mile... I wear a heart rate monitor, and while
that is still just an educated guess by a machine, 40 cal per mile has been
my average for all my rides. I guess it is because I tend to maintain a
certain heart rate regardless of terrain. If it is hilly, I go slower, if
it is flat, I go faster, but my hr stays about the same.

Roger Zoul said:

Joe wrote:
:: I've been dieting and I'm curious to see how many calories riding my
:: bike an hour per day through a wooded trail burns. I bike at a
:: moderate pace between 10-15 mph and if I do a calculation on this
:: site I get numbers in the 700 range.
::
:: http://dftools.ivillage.com/healthtools/calc_cb.cfm
::
:: My wife seems to think that number is way too high since she says
:: riding the exercise bike at the gym for one hour burns 1/2 that. I'm
:: trying to count my calories burned per day and I'd really like to get
:: an accurate number to put on my chart. Which would be correct?

I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400 kcals. 15
miles = 600 kcals.
20 miles = 800 kcals. Note, riding faster means you go more miles in an
hour, so that's how you burn more calories. For the most part, though,
you're doing the same about of work regardless of speed. Hence, the energy
used should really have little (to the first order) to do with speed.

I think the numbers at the site are too high.

Not really enough information. Need rider and bike weight, a good
guess at cross section, and info on tire type.

FWIW, a few years back I started collecting formulas for cycling
calories. I think I ended up with five different formulas -- not
surprisingly, I got five different answers, which typically varied by
up to 2.5X.

Oh yeah, the difference between 10 and 15 mph matters more on the road
-- the aerodynamic drag isn't significant in the gym.

Pat

Email address works as is.

Patrick Lamb wrote:
:: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul"
:: <[email hidden]> wrote:
::: Joe wrote:
::::: I've been dieting and I'm curious to see how many calories riding
::::: my bike an hour per day through a wooded trail burns. I bike at a
::::: moderate pace between 10-15 mph and if I do a calculation on this
::::: site I get numbers in the 700 range.
:::::
::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm
:::::
::::: My wife seems to think that number is way too high since she says
::::: riding the exercise bike at the gym for one hour burns 1/2 that.
::::: I'm trying to count my calories burned per day and I'd really
::::: like to get an accurate number to put on my chart. Which would be
::::: correct?
:::
::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
::: kcals. 15 miles = 600 kcals.
::: 20 miles = 800 kcals. Note, riding faster means you go more miles
::: in an hour, so that's how you burn more calories. For the most
::: part, though, you're doing the same about of work regardless of
::: speed. Hence, the energy used should really have little (to the
::: first order) to do with speed.
:::
::: I think the numbers at the site are too high.
::
:: Not really enough information. Need rider and bike weight, a good
:: guess at cross section, and info on tire type.

Not enough info for what? An extremely accurate answer? You're never gonna
get that. The 40 kcal/mile is not exact and is not perfect for everyone.
However, it's a lot more meaningful than the numbers that come out of that
website, and those that come out of devices like the Polar 720i or the Edge
305, which are all way too high.

::
:: FWIW, a few years back I started collecting formulas for cycling
:: calories. I think I ended up with five different formulas -- not
:: surprisingly, I got five different answers, which typically varied by
:: up to 2.5X.
::
:: Oh yeah, the difference between 10 and 15 mph matters more on the
:: road -- the aerodynamic drag isn't significant in the gym.

I won't argue that. But you still can't tell me exactly how many calories I
burn on a 10 or 15 mile road ride. Sure, drag makes a difference, but it
ain't that big of a difference.

Roger Zoul said:

Patrick Lamb wrote:

:: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul":: <[email hidden]> wrote:
::: Joe wrote:

::::: I've been dieting and I'm curious to see how many calories riding
::::: my bike an hour per day through a wooded trail burns. I bike at a
::::: moderate pace between 10-15 mph and if I do a calculation on this
::::: site I get numbers in the 700 range.
:::::
:::::http://dftools.ivillage.com/healthtools/calc_cb.cfm
:::::
::::: My wife seems to think that number is way too high since she says
::::: riding the exercise bike at the gym for one hour burns 1/2 that.
::::: I'm trying to count my calories burned per day and I'd really
::::: like to get an accurate number to put on my chart. Which would be
::::: correct?
:::
::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
::: kcals. 15 miles = 600 kcals.
::: 20 miles = 800 kcals. Note, riding faster means you go more miles
::: in an hour, so that's how you burn more calories. For the most
::: part, though, you're doing the same about of work regardless of
::: speed. Hence, the energy used should really have little (to the
::: first order) to do with speed.
:::
::: I think the numbers at the site are too high.
::
:: Not really enough information. Need rider and bike weight, a good
:: guess at cross section, and info on tire type.

Not enough info for what? An extremely accurate answer? You're never gonna
get that. The 40 kcal/mile is not exact and is not perfect for everyone.
However, it's a lot more meaningful than the numbers that come out of that
website, and those that come out of devices like the Polar 720i or the Edge
305, which are all way too high.

::
:: FWIW, a few years back I started collecting formulas for cycling
:: calories. I think I ended up with five different formulas -- not
:: surprisingly, I got five different answers, which typically varied by
:: up to 2.5X.
::
:: Oh yeah, the difference between 10 and 15 mph matters more on the
:: road -- the aerodynamic drag isn't significant in the gym.

I won't argue that. But you still can't tell me exactly how many calories I
burn on a 10 or 15 mile road ride. Sure, drag makes a difference, but it
ain't that big of a difference.

Drag can make all the difference, especialy at speeds above 15mph. I
got this quote, " Drag from the air isn't a big problem at low speeds.
However, it has one unsavory characteristic: the force required to
overcome air drag rises as the square of the speed" from here ...
http://users.frii.com/katana/biketext.html (about half way down the
page). That's why some online power (and hence calorie) calculators
ask for air temperature and altitude so air denisty can be included in
the calculation. e.g. http://www.kreuzotter.de/english/espeed.htm

Joe said:

I've been dieting and I'm curious to see how many calories riding my
bike an hour per day through a wooded trail burns. I bike at a
moderate pace between 10-15 mph and if I do a calculation on this site
I get numbers in the 700 range.

http://dftools.ivillage.com/healthtools/calc_cb.cfm

My wife seems to think that number is way too high since she says
riding the exercise bike at the gym for one hour burns 1/2 that. I'm
trying to count my calories burned per day and I'd really like to get
an accurate number to put on my chart. Which would be correct?

A stationary bike has lots of differences. No hills, no wind
resistance and even the weight of the bike matters less. No calc will
be perfect since the terrain can have a lot to do with it; and unless
it takes into account the type of bike it will be very generalized.

Most calcs give me 700 cals/hr at 11.5 mph on a mountain bike (+/-
10%) for my weight. Since they agree pretty closely, I am content
with that estimation.
http://www.caloriesperhour.com/index_burn.html

http://www.healthstatus.com/cgi-bin/calc/calculator.cgi

http://www.nutristrategy.com/activitylist.htm

With my stats, these agree at 768, 683, 732. These also agree with an
old cyclo computer I had that included cals burned.

I think these are conservative because they are based on general
biking. There is a BIG diff between a MTB and road bike, and there
are 2 climbs I almost always include in rides.

Marz wrote:
:: On Jul 27, 5:25 am, "Roger Zoul" <[email hidden]> wrote:
::: Patrick Lamb wrote:
:::
::::: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul"::
::::: <[email hidden]> wrote:
:::::: Joe wrote:
:::
:::::::: I've been dieting and I'm curious to see how many calories
:::::::: riding my bike an hour per day through a wooded trail burns. I
:::::::: bike at a moderate pace between 10-15 mph and if I do a
:::::::: calculation on this site I get numbers in the 700 range.
::::::::
:::::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm
::::::::
:::::::: My wife seems to think that number is way too high since she
:::::::: says riding the exercise bike at the gym for one hour burns
:::::::: 1/2 that. I'm trying to count my calories burned per day and
:::::::: I'd really like to get an accurate number to put on my chart.
:::::::: Which would be correct?
::::::
:::::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
:::::: kcals. 15 miles = 600 kcals.
:::::: 20 miles = 800 kcals. Note, riding faster means you go more
:::::: miles in an hour, so that's how you burn more calories. For the
:::::: most part, though, you're doing the same about of work
:::::: regardless of speed. Hence, the energy used should really have
:::::: little (to the first order) to do with speed.
::::::
:::::: I think the numbers at the site are too high.
:::::
::::: Not really enough information. Need rider and bike weight, a good
::::: guess at cross section, and info on tire type.
:::
::: Not enough info for what? An extremely accurate answer? You're
::: never gonna get that. The 40 kcal/mile is not exact and is not
::: perfect for everyone. However, it's a lot more meaningful than the
::: numbers that come out of that website, and those that come out of
::: devices like the Polar 720i or the Edge 305, which are all way too
::: high.
:::
:::::
::::: FWIW, a few years back I started collecting formulas for cycling
::::: calories. I think I ended up with five different formulas -- not
::::: surprisingly, I got five different answers, which typically
::::: varied by
::::: up to 2.5X.
:::::
::::: Oh yeah, the difference between 10 and 15 mph matters more on the
::::: road -- the aerodynamic drag isn't significant in the gym.
:::
::: I won't argue that. But you still can't tell me exactly how many
::: calories I burn on a 10 or 15 mile road ride. Sure, drag makes a
::: difference, but it ain't that big of a difference.
::
:: Drag can make all the difference, especialy at speeds above 15mph. I
:: got this quote, " Drag from the air isn't a big problem at low
:: speeds. However, it has one unsavory characteristic: the force
:: required to overcome air drag rises as the square of the speed" from
:: here ... http://users.frii.com/katana/biketext.html (about half way
:: down the page). That's why some online power (and hence calorie)
:: calculators ask for air temperature and altitude so air denisty can
:: be included in the calculation. e.g.
:: http://www.kreuzotter.de/english/espeed.htm

Sure....Again, I don't argue that point. But keep in mind that most people
going much above 15 mph for long with want a more aggressive position to
reduce drag to continue to go fast, thus reducing the calories expended.
Furthermore, those who don't adopt that position will probably not spend
that much time at high speeds working to overcome the force. Hence, as a
good estimate, that 40kals/mile is probably still much better than the
online calculators. At least the one used by the OP....

VBadJuJu wrote:
::
:: Most calcs give me 700 cals/hr at 11.5 mph on a mountain bike (+/-
:: 10%) for my weight. Since they agree pretty closely, I am content
:: with that estimation.
:: http://www.caloriesperhour.com/index_burn.html
::
:: http://www.healthstatus.com/cgi-bin/calc/calculator.cgi
::
:: http://www.nutristrategy.com/activitylist.htm
::
:: With my stats, these agree at 768, 683, 732. These also agree with
:: an old cyclo computer I had that included cals burned.

Just because they mostly agree doesn't mean any of them are correct.

::
:: I think these are conservative because they are based on general
:: biking. There is a BIG diff between a MTB and road bike, and there
:: are 2 climbs I almost always include in rides.

Roger Zoul said:

VBadJuJu wrote:
::
:: Most calcs give me 700 cals/hr at 11.5 mph on a mountain bike (+/-
:: 10%) for my weight. Since they agree pretty closely, I am content
:: with that estimation.
:: http://www.caloriesperhour.com/index_burn.html
::
:: http://www.healthstatus.com/cgi-bin/calc/calculator.cgi
::
:: http://www.nutristrategy.com/activitylist.htm
::
:: With my stats, these agree at 768, 683, 732. These also agree with
:: an old cyclo computer I had that included cals burned.

Just because they mostly agree doesn't mean any of them are correct.

On what basis would you assume those numbers are incorrect?

I know, just from basic conservation-of-energy physics, assuming
20% metabolic efficiency (the latter number is from Bicycling Science)
that raising my body+bike 500 feet in elevation must cost me 150 kcal
in addition to whatever it takes to move the bicycle. If the level
ground number were 40 kcal/mile at the speed I'm going that suggests
that a mile of 10% hill might cost 190 kcal, and 2 miles of 5% hill might
cost 230 kcal. Yet I can climb at 2500 feet/hour on hills like that even
on a moderately bad day, and I'm usually among the slowest cyclists on the
hills I climb.

2500 feet/hour will hence cost well over 750 kcal/hour. 750 kcal/hour
(again at 20% metabolic efficiency) represents an average power output
of 175 Watts. 2500 feet/hour of climbing is a speed of 5 mph on a 10%
hill or 10 mph on a 5% hill. This doesn't seem unreasonable for a
basically fit cyclist.

On the other hand, I agree the original poster is unlikely to have
spent anywhere close to 1200 kcal doing a 12 mile ride with 500 feet of
climbing.

Dennis Ferguson

Roger Zoul said:

Patrick Lamb wrote:
:: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul"
:: <[email hidden]> wrote:
::: Joe wrote:
::::: I've been dieting and I'm curious to see how many calories riding
::::: my bike an hour per day through a wooded trail burns. I bike at a
::::: moderate pace between 10-15 mph and if I do a calculation on this
::::: site I get numbers in the 700 range.
:::::
::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm

....

Quoted message said:

:::
::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
::: kcals. 15 miles = 600 kcals.
::: 20 miles = 800 kcals. Note, riding faster means you go more miles
::: in an hour, so that's how you burn more calories. For the most
::: part, though, you're doing the same about of work regardless of
::: speed. Hence, the energy used should really have little (to the
::: first order) to do with speed.
:::
::: I think the numbers at the site are too high.
::
:: Not really enough information. Need rider and bike weight, a good
:: guess at cross section, and info on tire type.

Not enough info for what? An extremely accurate answer? You're never gonna
get that. The 40 kcal/mile is not exact and is not perfect for everyone.
However, it's a lot more meaningful than the numbers that come out of that
website, and those that come out of devices like the Polar 720i or the Edge
305, which are all way too high.

That's fine, for some people it surely is close to 40 kcal/mile. But if
the OP weighs twice what you weigh, I bet he'll burn more than that. If
you're on a road bike with high pressure tires, and the OP is sitting up
on a cruiser with fat tires pumped up to 35 psi, he'll burn more than
that. If your claim is that all bicycle riders, no matter what
circumstances, burn about 40 Cal/mi, you're being fatuous.

Quoted message said:

:: FWIW, a few years back I started collecting formulas for cycling
:: calories. I think I ended up with five different formulas -- not
:: surprisingly, I got five different answers, which typically varied by
:: up to 2.5X.
::
:: Oh yeah, the difference between 10 and 15 mph matters more on the
:: road -- the aerodynamic drag isn't significant in the gym.

I won't argue that. But you still can't tell me exactly how many calories I
burn on a 10 or 15 mile road ride. Sure, drag makes a difference, but it
ain't that big of a difference.

Maybe for you. I'll argue that there's a knee in the energy vs. speed
curve. At speeds above the knee, aerodynamic drag becomes significant.
And the location of the knee depends on the factors listed above, and
perhaps other factors.

Pat

Patrick Lamb wrote:
:: Roger Zoul wrote:
::: Patrick Lamb wrote:
::::: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul"
::::: <[email hidden]> wrote:
:::::: Joe wrote:
:::::::: I've been dieting and I'm curious to see how many calories
:::::::: riding my bike an hour per day through a wooded trail burns. I
:::::::: bike at a moderate pace between 10-15 mph and if I do a
:::::::: calculation on this site I get numbers in the 700 range.
::::::::
:::::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm
:: ...
::::::
:::::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
:::::: kcals. 15 miles = 600 kcals.
:::::: 20 miles = 800 kcals. Note, riding faster means you go more
:::::: miles in an hour, so that's how you burn more calories. For the
:::::: most part, though, you're doing the same about of work
:::::: regardless of speed. Hence, the energy used should really have
:::::: little (to the first order) to do with speed.
::::::
:::::: I think the numbers at the site are too high.
:::::
::::: Not really enough information. Need rider and bike weight, a good
::::: guess at cross section, and info on tire type.
:::
::: Not enough info for what? An extremely accurate answer? You're
::: never gonna get that. The 40 kcal/mile is not exact and is not
::: perfect for everyone. However, it's a lot more meaningful than the
::: numbers that come out of that website, and those that come out of
::: devices like the Polar 720i or the Edge 305, which are all way too
::: high.
::
:: That's fine, for some people it surely is close to 40 kcal/mile.
:: But if the OP weighs twice what you weigh, I bet he'll burn more
:: than that.

I agree.

If you're on a road bike with high pressure tires, and
:: the OP is sitting up on a cruiser with fat tires pumped up to 35
:: psi, he'll burn more than that.

I agree.

If your claim is that all bicycle
:: riders, no matter what circumstances, burn about 40 Cal/mi, you're
:: being fatuous.

Did you read that anywhere? I'm saying its a good ball park rather than the
site.

::
::::: FWIW, a few years back I started collecting formulas for cycling
::::: calories. I think I ended up with five different formulas -- not
::::: surprisingly, I got five different answers, which typically
::::: varied by up to 2.5X.
:::::
::::: Oh yeah, the difference between 10 and 15 mph matters more on the
::::: road -- the aerodynamic drag isn't significant in the gym.
:::
::: I won't argue that. But you still can't tell me exactly how many
::: calories I burn on a 10 or 15 mile road ride. Sure, drag makes a
::: difference, but it ain't that big of a difference.
::
:: Maybe for you. I'll argue that there's a knee in the energy vs.
:: speed curve. At speeds above the knee, aerodynamic drag becomes
:: significant. And the location of the knee depends on the factors
:: listed above, and perhaps other factors.

From a practical POV, it won't make a difference. Either you'll get low to
lessen the drag or you'll be slowed by it.

Dennis Ferguson wrote:
:: On 2007-07-27, Roger Zoul <[email hidden]> wrote:
::: VBadJuJu wrote:
:::::
::::: Most calcs give me 700 cals/hr at 11.5 mph on a mountain bike (+/-
::::: 10%) for my weight. Since they agree pretty closely, I am content
::::: with that estimation.
::::: http://www.caloriesperhour.com/index_burn.html
:::::
::::: http://www.healthstatus.com/cgi-bin/calc/calculator.cgi
:::::
::::: http://www.nutristrategy.com/activitylist.htm
:::::
::::: With my stats, these agree at 768, 683, 732. These also agree
::::: with an old cyclo computer I had that included cals burned.
:::
::: Just because they mostly agree doesn't mean any of them are correct.
::
:: On what basis would you assume those numbers are incorrect?
::

Is VBadJuJU claiming a 10% hill above? Since he listed 700 cal/hr @ 11.5
mph, I assumed he was giving a variance in either speed or burn rate by
listing +/- 10%. Obviously, doing a 10% climb is going to burn seriously
more calories than a flat ride. The OP didn't mention any serious climbing.

I would challenge those numbers at that speed on the flats, but much less so
on a 10% hill.

:: I know, just from basic conservation-of-energy physics, assuming
:: 20% metabolic efficiency (the latter number is from Bicycling
:: Science) that raising my body+bike 500 feet in elevation must cost
:: me 150 kcal
:: in addition to whatever it takes to move the bicycle. If the level
:: ground number were 40 kcal/mile at the speed I'm going that suggests
:: that a mile of 10% hill might cost 190 kcal, and 2 miles of 5% hill
:: might cost 230 kcal. Yet I can climb at 2500 feet/hour on hills
:: like that even on a moderately bad day, and I'm usually among the
:: slowest cyclists on the hills I climb.
::
:: 2500 feet/hour will hence cost well over 750 kcal/hour. 750 kcal/hour
:: (again at 20% metabolic efficiency) represents an average power
:: output
:: of 175 Watts. 2500 feet/hour of climbing is a speed of 5 mph on a
:: 10% hill or 10 mph on a 5% hill. This doesn't seem unreasonable for
:: a basically fit cyclist.
::
:: On the other hand, I agree the original poster is unlikely to have
:: spent anywhere close to 1200 kcal doing a 12 mile ride with 500 feet
:: of climbing.
::
:: Dennis Ferguson

Roger Zoul said:

Patrick Lamb wrote:
:: Roger Zoul wrote:
::: Patrick Lamb wrote:
::::: On Thu, 26 Jul 2007 10:46:13 -0400, "Roger Zoul"
::::: <[email hidden]> wrote:
:::::: Joe wrote:
:::::::: I've been dieting and I'm curious to see how many calories
:::::::: riding my bike an hour per day through a wooded trail burns. I
:::::::: bike at a moderate pace between 10-15 mph and if I do a
:::::::: calculation on this site I get numbers in the 700 range.
::::::::
:::::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm
:: ...
::::::
:::::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
:::::: kcals. 15 miles = 600 kcals.
:::::: 20 miles = 800 kcals. Note, riding faster means you go more
:::::: miles in an hour, so that's how you burn more calories. For the
:::::: most part, though, you're doing the same about of work
:::::: regardless of speed. Hence, the energy used should really have
:::::: little (to the first order) to do with speed.
::::::
:::::: I think the numbers at the site are too high.
:::::
::::: Not really enough information. Need rider and bike weight, a good
::::: guess at cross section, and info on tire type.
:::
::: Not enough info for what? An extremely accurate answer? You're
::: never gonna get that. The 40 kcal/mile is not exact and is not
::: perfect for everyone. However, it's a lot more meaningful than the
::: numbers that come out of that website, and those that come out of
::: devices like the Polar 720i or the Edge 305, which are all way too
::: high.
::
:: That's fine, for some people it surely is close to 40 kcal/mile.
:: But if the OP weighs twice what you weigh, I bet he'll burn more
:: than that.

I agree.

If you're on a road bike with high pressure tires, and
:: the OP is sitting up on a cruiser with fat tires pumped up to 35
:: psi, he'll burn more than that.

I agree.

If your claim is that all bicycle
:: riders, no matter what circumstances, burn about 40 Cal/mi, you're
:: being fatuous.

Did you read that anywhere? I'm saying its a good ball park rather than the
site.

::
::::: FWIW, a few years back I started collecting formulas for cycling
::::: calories. I think I ended up with five different formulas -- not
::::: surprisingly, I got five different answers, which typically
::::: varied by up to 2.5X.
:::::
::::: Oh yeah, the difference between 10 and 15 mph matters more on the
::::: road -- the aerodynamic drag isn't significant in the gym.
:::
::: I won't argue that. But you still can't tell me exactly how many
::: calories I burn on a 10 or 15 mile road ride. Sure, drag makes a
::: difference, but it ain't that big of a difference.
::
:: Maybe for you. I'll argue that there's a knee in the energy vs.
:: speed curve. At speeds above the knee, aerodynamic drag becomes
:: significant. And the location of the knee depends on the factors
:: listed above, and perhaps other factors.

From a practical POV, it won't make a difference. Either you'll get low to
lessen the drag or you'll be slowed by it.

The 40 kcal/mi looks good to me. I have a MTB with wide tires and
usually ride on a gravel rail-trail at 8-12 mph. The hills have to
average out- more up, less down- if you start and end at the same point.
I remember from my road-running days we used 100 kcal/mi; the bike has
to be at least twice as efficient.

--
-------------------------------------------------------
"Every day is Saturday when you're retired."

Bob Burns
Mill Hall PA
(email is a spamtrap)

Roger Zoul said:

VBadJuJu wrote:
::
:: Most calcs give me 700 cals/hr at 11.5 mph on a mountain bike (+/-
:: 10%) for my weight. Since they agree pretty closely, I am content
:: with that estimation.
:: http://www.caloriesperhour.com/index_burn.html
::
:: http://www.healthstatus.com/cgi-bin/calc/calculator.cgi
::
:: http://www.nutristrategy.com/activitylist.htm
::
:: With my stats, these agree at 768, 683, 732. These also agree with
:: an old cyclo computer I had that included cals burned.

Just because they mostly agree doesn't mean any of them are correct.

And there is no reason to suspect they are all grossly in error
either.

They are very generalized in that they take into consideration only
rider weight and time with some considering speed but not bike or
terrain type. Even finer distinctions like tire characteristics are
ignored, but I am comfortable with the estimations.

Roger Zoul said:

Joe wrote:
:: I've been dieting and I'm curious to see how many calories riding my
:: bike an hour per day through a wooded trail burns. I bike at a
:: moderate pace between 10-15 mph and if I do a calculation on this
:: site I get numbers in the 700 range.
::
:: http://dftools.ivillage.com/healthtools/calc_cb.cfm
::
:: My wife seems to think that number is way too high since she says
:: riding the exercise bike at the gym for one hour burns 1/2 that. I'm
:: trying to count my calories burned per day and I'd really like to get
:: an accurate number to put on my chart. Which would be correct?

I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400 kcals. 15
miles = 600 kcals.
20 miles = 800 kcals. Note, riding faster means you go more miles in an
hour, so that's how you burn more calories. For the most part, though,
you're doing the same about of work regardless of speed. Hence, the energy
used should really have little (to the first order) to do with speed.

That is as generalized as any of the calculators. It might be an
accurate estimation for you, your weight, your bike, your riding
style and your speed, but probably only a valid rule of thumb for you
and those with ride characteristics like yours.

Quoted message said:

I think the numbers at the site are too high.

They seem a bit low depending on how much common sense you use in
selecting the pace. 10-11.9 mph is listed as slow, light effort. For
me that is an accurate characterization for the hydrid, but a ride
average of 11.6 or more on the MTB is far from light effort (and more
so the longer the ride is).

If I select by effort level the numbers rise to match most every other
estimation I have seen. Because they all converge to some degree, I
suspect the calcs are all derived from a scientific study they have
access to.

VBadJuJu wrote:
:: "Roger Zoul" <[email hidden]> wrote:
::
::: Joe wrote:
::::: I've been dieting and I'm curious to see how many calories riding
::::: my bike an hour per day through a wooded trail burns. I bike at a
::::: moderate pace between 10-15 mph and if I do a calculation on this
::::: site I get numbers in the 700 range.
:::::
::::: http://dftools.ivillage.com/healthtools/calc_cb.cfm
:::::
::::: My wife seems to think that number is way too high since she says
::::: riding the exercise bike at the gym for one hour burns 1/2 that.
::::: I'm trying to count my calories burned per day and I'd really
::::: like to get an accurate number to put on my chart. Which would be
::::: correct?
:::
::: I count 40 kcals/mile, no matter how fast I ride. 10 miles = 400
::: kcals. 15 miles = 600 kcals.
::: 20 miles = 800 kcals. Note, riding faster means you go more miles
::: in an hour, so that's how you burn more calories. For the most
::: part, though, you're doing the same about of work regardless of
::: speed. Hence, the energy used should really have little (to the
::: first order) to do with speed.
::
:: That is as generalized as any of the calculators. It might be an
:: accurate estimation for you, your weight, your bike, your riding
:: style and your speed, but probably only a valid rule of thumb for you
:: and those with ride characteristics like yours.

Well, you seem to think those numbers are special for a rule-of-thumb for
me, but I don't think that's especially true at all. I think they work best
for a typical average rider, as a good estimate.

::
::: I think the numbers at the site are too high.
::
:: They seem a bit low depending on how much common sense you use in
:: selecting the pace. 10-11.9 mph is listed as slow, light effort.
:: For me that is an accurate characterization for the hydrid, but a
:: ride average of 11.6 or more on the MTB is far from light effort
:: (and more so the longer the ride is).

Well, everything but the first sentence makes good sense to me. Just
because you pick your level of effort correctly still doesn't give you a
meaningful estimate of calories used.

::
:: If I select by effort level the numbers rise to match most every
:: other estimation I have seen. Because they all converge to some
:: degree, I suspect the calcs are all derived from a scientific study
:: they have access to.

Do you have some references for this? If so, I'd be curious to see them.

I have a polar 720i and a Garmin 305. I did a 31-mile ride with about 1000
ft of climb on Saturday on a road bike. The Garmin claims burned ~2400
kcals. That site above claims ~1950 kcals. Fitday.com claims about 1900
kcals. Cyclistats (developed by GaryG) claims about 1300 kcals (about 41
kcals/mile).

For weight loss purposes, the lower number is wise. I'm not at all
convinced that there is sound scientific study behind all of these different
estimates - since they are all over the map.