Carbo loading

Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

wrote in message
...
Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.


I remember reading that the average person has 2200 to 2500 calories stored.
Now, if you are training hard and not replacing them then you will have
less. If you carbo load then you have the potential to increase this
number.

As far as racing goes, the rule of thumb I use is that you want to replace
between 20g of carbohydrate (training) and 60 g of carbohydrate (racing) per
hour. This seems to be the limit you can absorb... but a recent study found
that having different size molecules could dramatically increase this
(several types of sugar).

You are right to think about this, but don't over think it. Use your long
rides to experiment with what products and what amounts work best for you.
I think it is backwards to base your pace on the calories you have, instead
I would base my calories on my pace.

You should check out some 24 hour mountain bike racing forums and sites
because they have the same concerns. Hammer has a lot of information as
well and some nice products, but go a little overboad in my opinion.

On Feb 10, 1:04*pm, "TM" wrote:
wrote in message

...



Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

I remember reading that the average person has 2200 to 2500 calories stored.
Now, if you are training hard and not replacing them then you will have
less. *If you carbo load then you have the potential to increase this
number.

As far as racing goes, the rule of thumb I use is that you want to replace
between 20g of carbohydrate (training) and 60 g of carbohydrate (racing) per
hour. *This seems to be the limit you can absorb... but a recent study found
that having different size molecules could dramatically increase this
(several types of sugar).

You are right to think about this, but don't over think it. *Use your long
rides to experiment with what products and what amounts work best for you.
I think it is backwards to base your pace on the calories you have, instead
I would base my calories on my pace.

You should check out some 24 hour mountain bike racing forums and sites
because they have the same concerns. *Hammer has a lot of information as
well and some nice products, but go a little overboad in my opinion.

I've read most everything at Hammer, and other sites as well.

Your 60g is about 240 kcal which is probably right about what can be
absorbed by an average sized person. I'm 220lbs, so I figure I can
absorb more.

As far as pacing based on available calories, or the other way around,
there is no way I can replace anywhere near as many colories as I can
expend. For example at about 65% effort it is still 750kcal/hour.
Adding effort it easily goes over 1000 kcal/hour. Previous experience
has shown that at that rate, I sooner or later run out of juice, no
matter how much I eat. So I have to figure out what is a doable pace
for the amount of fuel I can process.

Joseph

wrote in message
...
On Feb 10, 1:04 pm, "TM" wrote:
wrote in message

...



Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

I remember reading that the average person has 2200 to 2500 calories
stored.
Now, if you are training hard and not replacing them then you will have
less. If you carbo load then you have the potential to increase this
number.

As far as racing goes, the rule of thumb I use is that you want to replace
between 20g of carbohydrate (training) and 60 g of carbohydrate (racing)
per
hour. This seems to be the limit you can absorb... but a recent study
found
that having different size molecules could dramatically increase this
(several types of sugar).

You are right to think about this, but don't over think it. Use your long
rides to experiment with what products and what amounts work best for you.
I think it is backwards to base your pace on the calories you have,
instead
I would base my calories on my pace.

You should check out some 24 hour mountain bike racing forums and sites
because they have the same concerns. Hammer has a lot of information as
well and some nice products, but go a little overboad in my opinion.

I've read most everything at Hammer, and other sites as well.

Your 60g is about 240 kcal which is probably right about what can be
absorbed by an average sized person. I'm 220lbs, so I figure I can
absorb more.

As far as pacing based on available calories, or the other way around,
there is no way I can replace anywhere near as many colories as I can
expend. For example at about 65% effort it is still 750kcal/hour.
Adding effort it easily goes over 1000 kcal/hour. Previous experience
has shown that at that rate, I sooner or later run out of juice, no
matter how much I eat. So I have to figure out what is a doable pace
for the amount of fuel I can process.

Joseph

Yes. I agree, to the point where it seems you are saying that you are going
to pace your race by calculations and not effort. I don't believe
calculations are useful that way. I think they are necessary for a fueling
strategy, but pace comes from trial and error in training. In other words,
calculate how to get the most fuel in your system before the race and how
much you can replace successfully each hour. Pace based on your experience
and real perceived effort, it's so complicated a science that it is best
understood as an art.

In short, I would hate to see you racing based on a math problem and finish
below your true potential.

Also, I've seen people be unhappy with their results and blame fueling
issues when it is really just the best they could do. Don't fall into that
trap and good luck!

On Feb 10, 2:10*pm, "TM" wrote:
wrote in message

...
On Feb 10, 1:04 pm, "TM" wrote:



wrote in message

...

Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

I remember reading that the average person has 2200 to 2500 calories
stored.
Now, if you are training hard and not replacing them then you will have
less. If you carbo load then you have the potential to increase this
number.

As far as racing goes, the rule of thumb I use is that you want to replace
between 20g of carbohydrate (training) and 60 g of carbohydrate (racing)
per
hour. This seems to be the limit you can absorb... but a recent study
found
that having different size molecules could dramatically increase this
(several types of sugar).

You are right to think about this, but don't over think it. Use your long
rides to experiment with what products and what amounts work best for you.
I think it is backwards to base your pace on the calories you have,
instead
I would base my calories on my pace.

You should check out some 24 hour mountain bike racing forums and sites
because they have the same concerns. Hammer has a lot of information as
well and some nice products, but go a little overboad in my opinion.

I've read most everything at Hammer, and other sites as well.

Your 60g is about 240 kcal which is probably right about what can be
absorbed by an average sized person. I'm 220lbs, so I figure I can
absorb more.

As far as pacing based on available calories, or the other way around,
there is no way I can replace anywhere near as many colories as I can
expend. For example at about 65% effort it is still 750kcal/hour.
Adding effort it easily goes over 1000 kcal/hour. Previous experience
has shown that at that rate, I sooner or later run out of juice, no
matter how much I eat. So I have to figure out what is a doable pace
for the amount of fuel I can process.

Joseph

Yes. *I agree, to the point where it seems you are saying that you are going
to pace your race by calculations and not effort. *I don't believe
calculations are useful that way. *I think they are necessary for a fueling
strategy, but pace comes from trial and error in training. *In other words,
calculate how to get the most fuel in your system before the race and how
much you can replace successfully each hour. *Pace based on your experience
and real perceived effort, it's so complicated a science that it is best
understood as an art.

In short, I would hate to see you racing based on a math problem and finish
below your true potential.

Also, I've seen people be unhappy with their results and blame fueling
issues when it is really just the best they could do. *Don't fall into that
trap and good luck!

Art indeed! My previous efforts have been more seat-of-the-pants, and
I while I have been satisfied with the results, I felt they were sub
optimal. Particularly in the longer races, where I ran out of energy.
I also started out too fast, so that complicates the issue.

My idea is to mathematically guestimate a suitable pace, and then try
that pace on training rides, and adjust based on who knows what. I
want a pace that looks good on paper for long distance, and is tested
in shorter distances, rather than a pace that is tested on shorter
distances and just hoped for in terms of long distance.

Even the best laid plans can fall by the wayside underway, so this is
mor eor less just to give my pacing strategy a general nudge one way
or the other.

Joseph

Art indeed! My previous efforts have been more seat-of-the-pants, and
I while I have been satisfied with the results, I felt they were sub
optimal. Particularly in the longer races, where I ran out of energy.
I also started out too fast, so that complicates the issue.

My idea is to mathematically guestimate a suitable pace, and then try
that pace on training rides, and adjust based on who knows what. I
want a pace that looks good on paper for long distance, and is tested
in shorter distances, rather than a pace that is tested on shorter
distances and just hoped for in terms of long distance.

Even the best laid plans can fall by the wayside underway, so this is
mor eor less just to give my pacing strategy a general nudge one way
or the other.

Joseph


Another point. Your calculations aren't taking into consideration fat and
what percent of your energy is coming from it versus glycogen (variable
according to effort and trainable over time). You see how messy this gets?
You need to figure out how many calories you can successfully digest at your
race pace, but beyond that you may be barking up the wrong tree as far as
determining that pace. Heart rate or watts may serve you better in
understanding what pace your body can handle for what length of time. One
of those is what I would use for what its worth.

On Feb 9, 4:45 am, "
wrote:

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

I don't really care and it doesn't matter anyway but there's some
stuff in the latter half of this that reviews the literatu
http://www.e-caps.com/downloads/JOE/joe_sep05.pdf

On Feb 10, 10:04*pm, "TM" wrote:
Art indeed! My previous efforts have been more seat-of-the-pants, and
I while I have been satisfied with the results, I felt they were sub
optimal. Particularly in the longer races, where I ran out of energy.
I also started out too fast, so that complicates the issue.

My idea is to mathematically guestimate a suitable pace, and then try
that pace on training rides, and adjust based on who knows what. I
want a pace that looks good on paper for long distance, and is tested
in shorter distances, rather than a pace that is tested on shorter
distances and just hoped for in terms of long distance.

Even the best laid plans can fall by the wayside underway, so this is
mor eor less just to give my pacing strategy a general nudge one way
or the other.

Joseph

Another point. *Your calculations aren't taking into consideration fat and
what percent of your energy is coming from it versus glycogen (variable
according to effort and trainable over time). *You see how messy this gets?
You need to figure out how many calories you can successfully digest at your
race pace, but beyond that you may be barking up the wrong tree as far as
determining that pace. *Heart rate or watts may serve you better in
understanding what pace your body can handle for what length of time. *One
of those is what I would use for what its worth.

I did take into account how much comes from fat and how much from
carbs. It's of course just an estimate. I've worked my way back from a
combination of watts and HR (as a proxy for VO2max) to determine the
CHO caloric expenditure at different paces. I've pretty much figured
that under 5 hours I can do whatever I want in a race. No worries
about fuel, as long as I eat a bit. There are other issues with going
too hard in this case, but running out of gas isn't one of them.

The problem with long races is running out of gas. When the race rolls
around, I'll be using average HR to pace, making on the fly
adjustments for drift, temp, etc.

If I can safely assume I won't run out of gas I'll up the pace to 75%
or so, otherwise I have to keep it down at 70%. Not that big a diff,
but over 24 hours it adds up.

Joseph

On Feb 9, 4:45*am, "
wrote:
Hi All,

Because I have nothing better to do, I've been pondering fueling
requirements for rides of different durations and intensities.

I know more or less how may Watts and thus kcal are required for me to
ride certain types of terrain at certain speeds.

I figure I can assimilate about 400kcal/hour of ingested carbs while
riding. This based on a 16mg/min/kg figure I found, plus a little
margin.

At a given intenisty, I know more or less what percent of VO2max this
requires, and thus have an idea of how much energy is derived from
fat, and how much from carbs. Then I can subtract the 400 to figure my
hourly carb deficit.

I haven't found any good numbers for how many kcal are stored in the
form of glycogen in the muslces and liver. I've just extrapolted from
a few numbers here and there I've seen as averages for average sized
folks. So I'm using 20kcal per kg of lean body weight.

Does anyone have better numbers for this? I also wonder how great an
effect carbo-loading would have in terms of available kcal. Everything
I see is about how many mmol/kg of glycogen is found in the muscles.
This doesn't tell me much, as I can't figure out what the molar mass
is of glycogen, and anyway is the kg the mass of the muscles? If
"normal" concentrations are 110 mmol/kg or so, and a successful carbo-
loading session boosts this to 190mmol/kg, what does that mean in
terms of available kcal?

This year there are 4 specific events I am concentrating on. One is
less than 2 hours which I can go all out without worrying about
running empty, another is about 4.5 hours which is borderline if I go
all out. The next is 24 hours which by necessity must be taken at a
more relaxed pace, probably in the range of 65-75% VO2max. With a
better idea of how many kcal I have in my body, I will be better able
to chose a reasonable pacing strategy. The same for a 16 hour event a
little later.

So how do I figure out how many kcal I have stored, and how many more
can be crammed in by carbo-loading?

Joseph

PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.


I don't know what kcal per kg or mmol/kg are, never heard of that
stuff.

But Roger De Vlaeminck and the rest of the Brooklyn guys use to
eat a large plate of pasta and steak cooked very rare just before
a big classic.

On Feb 10, 10:11*pm, wrote:
On Feb 9, 4:45 am, "

wrote:
PS: I know this probably should be filed under who-cares and/or it-
doesn't-matter-anyway, but humour me please.

I don't really care and it doesn't matter anyway but there's some
stuff in the latter half of this that reviews the literatuhttp://www.e-caps.com/downloads/JOE/joe_sep05.pdf

That was interesting. I found the "Energy Source During Exercise"
tables enlightening. It seems to suggest that muscle glycogen is used
prefferentially until it is used up, then the main supply of CHO
becomes the blood as regulated/produced by the liver, and limited in
amount by the absorbtion rate.

That would mean maintaing a constant pace would not be wise. Any pace
that could be ridden later on fats and blood sugar alone, would be
wasefully slow when there was muscle glycogen around.

So go fast until muscle glycogen is almost depleted, then go as fast
as is possible (which is slow) with the limited calories the liver can
pull from the intestines.

I had been thinking in terms of spreading the total available calories
evenly over the whole ride.

So fill the tanks to the brim, ride at a fast aerobic pace until
empty, then slog along as best possible to the finish.

Toward the end of the paper there is a table showing glycogen stores
in terms of g/kg for various circumstances. It says 21g/kg stored
glycogen in the muscles for a high CHO diet. It also shows 36g/kg for
a carbo-loaded scenario. the kg must be muscle, but what really
matters is that it is almost twice as much.

This suggests that if under normal circumstances I have 2500kcal
stored, I might be able to bump that to as many as 4000. That would
make a big difference in terms of how long I could keep up the fast
aerobic pace before dogging it.

Joseph