Endurance.Net Ridecamp Archives

Hmmm, you know if I was a lawyer I'd
get to charge you for this.  So you burn say 300 calories in an exercise
session, yet only some fraction of that is fat, why?  Fuel use is
based upon rate and capacity.  The rate at which energy can be provided
for muscle contractions is much faster with carbohydrate than fat. Far
fewer steps, and each step is time dependent.  Sort of like getting
things done by an efficient private business (carbohydrate) or by the government
(fat) which involves infinitely more steps and each requires time, but
also has tremendous resources or capacity.  So my guy running for
24 hours.  He used up about 12,500 calories in 24 hours, and about
5,000 came from fat, the rest from carbohydrate.  If he had run faster
those fractions would have changed such that even more carbohydrate would
have been used, and likely even less fat.  Ironically, people talk
about marathon running as if it uses fat......but to run a decent compettiive
marathon, say 2:30, as little as 10-20% or less of the energy comes from
fat.  Think about this, a lean fit individual becomes "tired"
at 20 miles into a marathon, and yet they have 10's of thousands of calories
stored as fat.  The harder you work, like one of those punishing buns
of steel classes,  the more total calories you utilize, true, but
as a % of that rate of energy use carbohydrate predominates.  Above
a walk more than 50% of our energy comes from carbohydrate.  The best
way to utilize fat, and therefore to burn fat, is more moderate paced,
longer duration activity. Uh I think they call it "brisk" walking.
 Exactly what our get thin quick, no dieting, not exercise, impatient
as all heck society doesn't want to hear.  If you can't carry on a
conversation, at least in some sor to f halting mannder, the intensity
is such that you are using mostly carbohydrate and that twinkie you crave
after that workout just replaced those calories.........and more.

So YES riding uses energy.  Lots
of muscles working at a sustained moderate pace, but if you don't lose
fat from this activity you are matching this with an equivalent energy
intake.  Riding should be great for all manner of health related benefits,
including weight loss, but if it isn't coupled with caloric restriction...then
weight loss? forget it.

I did the Lincoln trail 100 last year.
 I could do the math for you, but suffice to say the cheeseburger
(cold but tasty) that I ate at about the 80 mile mark (courtesy & thanks
to my friend Kelly Moore) was more total calories than I burned the whole
day from riding!  Its hard to truely lose weight from exercise alone.
 One has to bite the bullet and eat less.  Now  just eating
less and NOT being active is not going to do it for you either.  I
run a debate in one of my classes to argue for just diet or just exercise,
as if you can't combine the two.  The literature is pretty clear:
better to eat like s%&t and be active than eat like a rabbit and sit
on your a#%, from the persepctive of many health paramters, but to lose
weight the two really have to come together.


Jon K. Linderman, Ph.D., FACSM
Associate Professor of Health and Sport Science
University of Dayton
300 College Park
Dayton, OH 45469-1210
Voice:(937) 229-4207
FAX: (937) 229-4244
http://homepages.udayton.edu/~lindermj/