Calories Burned Question

[email hidden] wrote:
:: I am trying to find a calculator or equation that accurately
:: estimates calories burned. I have been using the formula of 0.28 cal
:: per pound per mile, but I am suspicious of the results I get with
:: this.
::
:: For example, right now I weigh 250 lbs and can do roughly 21 mph over
:: a 40k course ( mostly flat, about 500ft climbing total. Also, on a
:: standard road bike, normal position, no aero bars, normal wheels ).
:: This would put my calories per mile at 70, and per hour at 1470.
:: However, if I weighed what I should, 170lbs, to burn the same amount
:: of calories I would need to average almost 31 mph.( which would make
:: the calories even higher! due to more wind resistance) Now, I
:: should be able to burn the same amount, if not more so at the lower
:: weight, since I've only been training recently for 2 months, so I
:: suspect either 0.28 is too high or I will be national TT champ next
:: year ( not too likely, my best 40k was only about 55min at fighting
:: weight. and I am now 41 yrs old)
::
:: Does anyone know of a formula that can adjust for speed as well as
:: weight?

A good rule-of-thumb is around 37 to 42 kcals/mile. Higher side if you're
heavier and/or climbing a lot.

You can download cyclistats and use the program for free for the trail
period. It has the ability to let you enter your weight as well as that of
your bike and gear. Then you can factor in the climbing, type of bike and
position, and wind, if you wish.

www.cyclistats.com

I get nothing for recommending this, I'm just a user.

Roger Zoul said:

:: weight?

A good rule-of-thumb is around 37 to 42 kcals/mile. Higher side if you're
heavier and/or climbing a lot.

Yes, I think that is close for most riders, but I think the range is
wider than that, especially for heavier riders. I used to use around
40-45 kcal/mile when I was at ~170lbs and it seemed to be pretty
close. I would then add 25 or 33% if I was doing a lot of climbing.

I suspect the problem with using a set rate per pound per mile is
that, even if you are adding weight, there isn't a linear progression
of energy expended, like there would be for walking or running where
there are less confounding factors involved. I would think once you
get the weight moving, there is comparatively less energy used to
maintain the speed, even including going up and down hills and dead
spots in the pedal stroke etc.. I am no physics expert, so I wouldn't
know how to adjust correctly for that, but I suspect that is why the
set number is too high for a heavier rider. ( and that doesn't even go
into the differences per mile at different average speeds due to wind
resistance )

I will try that program and see what kind of numbers it comes up with
at the different weights. I doubt I would pay $50 solely for such
mundane information, but...

<[email hidden]> wrote in message
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Quoted message said:

Roger Zoul said:

:: weight?

A good rule-of-thumb is around 37 to 42 kcals/mile. Higher side if
you're
heavier and/or climbing a lot.

Yes, I think that is close for most riders, but I think the range is
wider than that, especially for heavier riders. I used to use around
40-45 kcal/mile when I was at ~170lbs and it seemed to be pretty
close. I would then add 25 or 33% if I was doing a lot of climbing.

My experience is that it is very easy to over count calories used by riding.
I suspect your numbers are too large.

Quoted message said:

I suspect the problem with using a set rate per pound per mile is
that, even if you are adding weight, there isn't a linear progression
of energy expended, like there would be for walking or running where
there are less confounding factors involved. I would think once you
get the weight moving, there is comparatively less energy used to
maintain the speed, even including going up and down hills and dead
spots in the pedal stroke etc.. I am no physics expert, so I wouldn't
know how to adjust correctly for that, but I suspect that is why the
set number is too high for a heavier rider. ( and that doesn't even go
into the differences per mile at different average speeds due to wind
resistance )

This is all nice to talk about, but impossible to factor into any useful
estimate of calories burned.

Quoted message said:

I will try that program and see what kind of numbers it comes up with
at the different weights. I doubt I would pay $50 solely for such
mundane information, but...

Well, the program does much, much more than compute calories burned! 🙂

Quoted message said:

Quoted message said:

I will try that program and see what kind of numbers it comes up with
at the different weights. I doubt I would pay $50 solely for such
mundane information, but...

Well, the program does much, much more than compute calories burned! 🙂

Yes it does, but I'm not interested in those things. It may be worth
$50 to somebody else, but not to ME 🙂

Getting back to the calories, the software calculated my original
example (250lbs/ 24 mi @ 20.5 mph)at 53kcal mile, which seemed pretty
good at first glance. However, the program also makes adjustments for
riding position, and gave the following results:

53 kcal/ mile on the hoods
44 kcal/ mile in the drops
40 kcal/ mile aero bars

It doesn't take a wind tunnel test to know that those adjustments are
way too high. And, indeed, if I adjust the numbers to burning
identical calories in each position, per the software I would ride at
approximately the following speeds:
20.5 mph on the hoods
24 mph in the drops
27 mph aero bars

Those must be the new aero bars, that give you a 20 mph tail-wind 🙂.
Does anybody know where they sell these?

<[email hidden]> wrote in message
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Quoted message said:

I am trying to find a calculator or equation that accurately estimates
calories burned. (snip)

It's 42 per mile.

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

Quoted message said:

I am trying to find a calculator or equation that accurately estimates
calories burned. (snip)

It's 42 per mile.