Hourly Calory Use -- [Was: Re: [at-l] Re: Weight Loss]

[jbullar1 at twcny.rr.com (Jim Bullard)]

At 11:47 AM 8/25/2005 -0400, greyowl@rcn.com wrote:

>What and violate the second law of thermodynamics??!!  The
>amount of work that is done is dependent only on the mass of
>the object and the distance that is to be moved.  (I really
>enjoyed college physics especially quantum physics)
>
>Grey Owl
>
> >You can't really reduce it to a formula except in a generalized
>sense. Take
> >Lance Armstrong for instance. He has an over sized heart and
>higher than
> >normal muscle efficiency (the capacity to turn fuel into
>energy). If an
> >individual's circulatory system is less efficient at getting fuel to
>the
> >muscles, if your muscles (in particular those muscles used for
>a given
> >activity) are of a less efficient type than the average then you
>will burn
> >more calories than the charts/calculators indicate. It also
>would vary with
> >how often you do it. As you become more accustomed to the
>activity your
> >efficiency may improve and you will burn fewer calories for
>the same amount
> >of exercise. I also suspect that running a given distance burns
>more
> >calories than walking it just as driving 'X' miles at 80 mph
>burns more gas
> >than driving the same distance at 50 mph.

And Rafe wrote:
>Work (energy) is force over a distance.  F delta s.
>
>Calories and foot-pounds are in the same units: energy (Joules).
>
>If your analysis were correct, a thru-hiker ought to require
>less and less food-per-mile as he/she improves in fitness
>along the way.  I don't think it works that way.
>
>Your automobile analogy works OK, because the
>force (wind resistance) term goes up with velocity,
>and total distance ('X' miles) is the same.

Yeah guys, I remember physics but... the efficiency of humans isn't as 
easily quantified as machines and the ratio of work accomplished does not 
necessarily to energy spent when variances in efficiency come into play 
even in physics. And I really do suspect that like any athlete a hiker's 
muscles become more efficient at converting food to energy as they become 
more accustomed to the activity. I noticed an effect like that when I was 
running. Hikers continue to require large amounts of food because they 
continue to burn large amounts of calories but in most accounts I've read 
the bulk of the weight loss occurs early on in the hike and tapers off as 
they get nearer the other end. I readily admit the difference in efficiency 
is probably small and probably more of the diminishing rate of weight loss 
is the result of increased intake than due to increased efficiency.