how many calories have been burned if.....

"Robert Walls" <rwalls.RemoveThis@emailwallsa.net> wrote:
> Subject: how many calories have been burned if.....
> ...you weigh 263 pounds, and walked 7.5 miles in an
> hour and 45 minutes?

That is a speed of about 4.3 MPH. According to the
Compendium [1], a "typical" 263-lb person burns about 600
kCal/hour when walking at 4.0 MPH and about 750 Cal/hr at
4.5 MPH. For 3.5 MPH and higher, kCal/hr seems to increase
linearly. So interpolating, I would estimate 690 kCal/hr
at 4.3 MPH.

Thus, a "typical" 263-lb person burns about 1208 calories
walking at 4.3 MPH for 1.75 hours.

But of course, no one is "typical" .

By the way, you can arrive at the same estimate by using the
calculator at http://www.caloriesperhour.com/index_burn.html.


-----

[1] http://prevention.sph.sc.edu/Tools/Compendium_tracking.pdf,
updated in 2000. Originally published by B.E. Ainsworth
et al, "Compendium of Physical Activities: Classification
of Energy Costs of Human Physical Activities", Medicine
and Science in Sports and Exercise, Vol. 25, No.1, 1993.

MS-SE is the journal of the ACSM. See http://www.ms-se.com.
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> >...you weigh 263 pounds, and walked 7.5 miles in an hour and 45 minutes?
>
> given your weight & pace, probably around 900-1000 give or take.
>
>
> >did this last night and it was a moderate effort, although my legs are
quite
> >sore today.
>
> Given the numbers you posted, you averaged 4.25mph
> I'm not doubting you, but someone your weight, not already an active
> walker (im assuming?), and going 7.5 miles at that pace would fall far
> far above a "moderate effort"... unless they were 7ft and had a huge
> stride.

> I can easily go 4mph, but I need something (music, something in front
> of me, etc) to keep at that pace or else I find myself eventually
> slowing down. And you averaged 4.25mph...
>
> So, anyways... just how tall are you?
>
>
> And fwiw, unless you are already an active walker & already in decent
> shape, I think the whole walking community would caution you about
> walking such distances this early, as it greatly increases the chance
> of injury.... work your distances up slowly.
>

I'm 6' tall and about 75 pounds overweight. Walking at my current speed
pushes up the hr to around 160-165. On a scale of 1/10, with 1 being no
effort and 10 being strenuous, I feel about 6/10 at this speed. I've been
walking off and on for 5 years. I got out of the hang of it for nearly a
year and am trying to get back to where I used to be. I normally don't walk
the 7.5 mph distance, but I wanted to see if it could be done after walking
for several weeks now and dropping 12 pounds. I was thinking of taking a
day next week and walking 10 miles at the same pace, but that will be a
definite no-go. For now, I'll stick with 5.7 miles and drop some more
weight first.

Just FYI, when I first started my walking program 5 years ago, I weighed
close to 280 pounds. I immediately started walking at 5.5 mph for as long
as I could initially, which wouldn't be more than 15 minute segments.
Gradually, I worked up to 40-45 minutes at that rate and my weight dropped
off like a hammer. However, that was in the days before I knew about heart
rate monitors, and when I finally did get one, I was shocked at how high my
hr would go- sometimes 190-195. This was dangerous even when I dropped to
230 pounds. Now, I watch it constantly and won't let it go above 160
normally (165 max for short periods). Sometimes I don't watch the monitor
and it will climb to 170-175 on warmer days. When my effort becomes 8/10, I
get it back down to 6/10 as soon as possible. When I used to walk at my
reckless 5.5 mph pace, my efforts were always 9-10/10. It amazes me now
that I ever stuck with it as long as I did, but I was encouraged by the
rapid weight loss. This time, I'm trying to play a safer game.

Rob
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No Spam <nospam RemoveThis @nospam.com> wrote:
> Given the numbers you posted, you averaged 4.25mph
> I'm not doubting you, but someone your weight, not already an active
> walker (im assuming?), and going 7.5 miles at that pace would fall far
> far above a "moderate effort"... unless they were 7ft and had a huge
> stride.

That was my first impression, as well. Then I crunched some
numbers. In the final analysis, I'm not sure I agree --
with one qualification.

I can maintain 4.3 MPH on a treadmill. I agree that it is
not "moderate effort" for me. But I am 69 inches tall, and
my aggressive stride is about 33 inches. I believe my legs
are shorter than normal proportions [1]. At 4.3 MPH, I
estimate that my pace is about 2.3 steps/sec (138/min) [2].
I peak at 4.5 MPH, which is about 2.4 steps/sec (144/min).

Robert said later that he is 6 feet tall. I estimate that
a person that tall normally has an aggressive stride of
38-40 inches. (Is that true for you, Robert?) At 4.3 MPH,
his pace is about 1.9 to 2.0 steps/sec (114-120/min). That
is equivalent to my walking at 3.6 to 3.8 MPH. For me, that
is indeed "moderate effort" -- at least at the low end.


-----

[1] http://www.worsleyschool.net/socialarts/body/proportions.html.

[2] With a 33-inch stride at 4.3 MPH, the pace is about
4.3*5280*12/33/3600 = 2.3 steps/sec.
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>
> That was my first impression, as well. Then I crunched some
> numbers. In the final analysis, I'm not sure I agree --
> with one qualification.
>
> I can maintain 4.3 MPH on a treadmill. I agree that it is
> not "moderate effort" for me. But I am 69 inches tall, and
> my aggressive stride is about 33 inches. I believe my legs
> are shorter than normal proportions [1]. At 4.3 MPH, I
> estimate that my pace is about 2.3 steps/sec (138/min) [2].
> I peak at 4.5 MPH, which is about 2.4 steps/sec (144/min).
>
> Robert said later that he is 6 feet tall. I estimate that
> a person that tall normally has an aggressive stride of
> 38-40 inches. (Is that true for you, Robert?) At 4.3 MPH,

I believe I have an aggressive stride, in fact maybe too aggressive.
Several people have observed me walking in the past and have commented on my
"overextending"- maybe not the exact term here, but something similar.
Perhaps that's why my foot arch muscles were so sore yesterday that I had to
take a day off. Still, it wouldn't be hard to measure stride length- the
next time I walk, I'll do it. As I mentioned, my personal "out of 10"
effort is about 6 which is moderate.... unless I'm not watching the heart
monitor and let bmp climb above 170 (and of course I'm getting up to 4.5
mph+ when this occurs too).

BTW, since you've been so helpful with the compendium link and its
explanation, let me ask you about something else I've heard about. Is there
a way to determine cardo fitness level by determining the number of
breathing cycles per minute? I seem to recall coming across some data on
this in the past, but I can't remember what it's called or how it works.
Thanks in advace for any info you can share.

Robert

> his pace is about 1.9 to 2.0 steps/sec (114-120/min). That
> is equivalent to my walking at 3.6 to 3.8 MPH. For me, that
> is indeed "moderate effort" -- at least at the low end.
>
>
> -----
>
> [1] http://www.worsleyschool.net/socialarts/body/proportions.html.
>
> [2] With a 33-inch stride at 4.3 MPH, the pace is about
> 4.3*5280*12/33/3600 = 2.3 steps/sec.
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I wrote:
> No Spam <nospam RemoveThis @nospam.com> wrote:
> > going 7.5 miles at that pace [4.25mph (sic)] would fall
> > far far above a "moderate effort"... unless they were
> > 7ft and had a huge stride.
> [....]
> I can maintain 4.3 MPH on a treadmill. I agree that it is
> not "moderate effort" for me. But I am 69 inches tall, and
> my aggressive stride is about 33 inches. I believe my legs
> are shorter than normal proportions [1]. At 4.3 MPH, I
> estimate that my pace is about 2.3 steps/sec (138/min) [2].
> I peak at 4.5 MPH, which is about 2.4 steps/sec (144/min).

I should clarify ....

First, I used the term "stride" in the vernacular, which is
equivalent to "step size" [1]. But in academic literature,
(gait) "stride" is based on two steps [2].

Second, I should not have characterized my gait as an
"aggressive" stride. That is misleading. I did not mean
to suggest an exaggerated gait.

Third, my 33-inch "step size" is at 4.3 MPH. Normally, step
size changes linearly with speed [3]. My measurements confirm
that. Based on belt speed and measured cadence (steps/min),
my estimated step size is 20.4 to 33.7 inches for walking
speeds of 2.0 to 4.5 MPH.

> Robert said later that he is 6 feet tall. I estimate that
> a person that tall normally has an aggressive stride of
> 38-40 inches. (Is that true for you, Robert?) At 4.3 MPH,
> his pace is about 1.9 to 2.0 steps/sec (114-120/min). That
> is equivalent to my walking at 3.6 to 3.8 MPH. For me, that
> is indeed "moderate effort" -- at least at the low end.

Although I believe my conclusion is valid (Robert's cadence at
4.3 MPH is about the same as my estimated cadence at 3.7 MPH,
which is "high moderate" effort for me), my numbers are probably
far off the mark. They were based on an imperfect model.

Using a better model -- and not trying to "normalize" my
proportions -- I estimate that Robert's "step size" is about
35.2 inches at 4.3 MPH, with a cadence of about 129 steps/min.

That is only a first approximation; there are a lot of
unpredictable variables. But I think it demonstrates the
point I wanted to make, namely: 4.3 MPH might not be "far
far above moderate effort", and the person does not have to
be "7 ft and [have] a huge stride" for that to be the case.


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[1] http://www.hyperdictionary.com/dictionary/stride

[2] http://www.oandp.org/jpo/library/1997_01_010.asp

Similar to one definition in Webster's Collegiate
Dictionary.

[3] http://www.cs.umd.edu/~chiraz/biomet02.pdf
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