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How long before aerobics "kicks in"??



 
 
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  #1  
Old July 3rd 03, 12:06 PM
Van Bagnol
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Default How long before aerobics "kicks in"??

In article ,
"MartinB" wrote:

Well - there's a sign on the gym wall that says "you need carbs to
burn fat".

But is this correct?????


It not _quite_ that simple. You can burn fat without carbs -- after all,
hibernating animals burn only fat all winter -- however, the total
calorie burn is pretty low. Theoretically, the highest fat calorie
expenditure on a _percentage basis_ is when you are sleeping! While it
works for grizzlies, hibernating for 3-4 months with zero meals is not a
popular weight loss method among humans. ;-)

To burn more calories, you have to be more active than that. So, you
increase your activity by exercise -- the more intense and/or longer the
duration, the more calories burned.

But when you exercise more intensely, not all of the energy production
will be able to come from fatty acids that your fat stores provide. A
certain percentage of muscle tissue will face shortfalls of the oxygen
it needs, so glucose from the body's glycogen stores is necessary to
"keep the flame going", so to speak, and provide energy to muscle tissue
momentarily starved for oxygen. You can get by with existing body
glycogen for a little while, but you will eventually have to replenish
it -- with carbs.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
....enjoys - Theatre / Windsurfing / Skydiving / Mountain Biking
....feels - "Parang lumalakad ako sa loob ng paniginip"
....thinks - "An Error is Not a Mistake ... Unless You Refuse to Correct It"
  #2  
Old July 3rd 03, 02:48 PM
Peter Webb
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Default How long before aerobics "kicks in"??

SNIP

To burn more calories, you have to be more active than that. So, you
increase your activity by exercise -- the more intense and/or longer the
duration, the more calories burned.

But when you exercise more intensely, not all of the energy production
will be able to come from fatty acids that your fat stores provide. A
certain percentage of muscle tissue will face shortfalls of the oxygen
it needs, so glucose from the body's glycogen stores is necessary to
"keep the flame going", so to speak, and provide energy to muscle tissue
momentarily starved for oxygen. You can get by with existing body
glycogen for a little while, but you will eventually have to replenish
it -- with carbs.


Absolute crap. Why can't "all of your energy come from fatty acids that your
fat stores provide"? More to the point, people on zero carb diets obviously
can and do manage to exercise intensely.

BTW, glycogen can also be replenished by metabolising protein through
gluconeogenesis. People on zero carb diets do not have zero glucose or zero
glycogen levels.

The OP was contemplating a low carb diet, but worried that this would make
him stop his exercise regime. It most definitely would not. Low carb diets
are doubly effective if combined with plenty of aerobic exercise.







  #3  
Old July 3rd 03, 08:18 PM
Mongie
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Default How long before aerobics "kicks in"??


Absolute crap. Why can't "all of your energy come from fatty acids that

your
fat stores provide"? More to the point, people on zero carb diets

obviously
can and do manage to exercise intensely.


I'd be interested if you could point me in the direction of just one person
on a "zero carb" diet who successfully manages to "exercise intensely".

Define "intensely".

I do approx 95 mins "intense" cardio per day (and by "intense" I mean at the
rate of 22 calories per minute) - my aim is to burn 2000 calories per day.

Completely unintentionally, and due to circumstances, on Monday of last week
my carb intake was 50g. However, I made a point of hammering the protein
that day to ensure my calorie intake was sufficient.

Tuesday's workout was a disaster..........I got to 670 calories and
*bang*........I hit the proverbial brick wall and I wasn't going anywhere
further.

Conclusion: my lack of carb intake on the previous day had an adverse effect
on my endeavours to work out.

I hate carbs as much as the next person but I begrudgingly concede (from
personal experience) that they're necessary, nay essential, to be able to
undertake intense cardio activity with any degree of success.

However, I'm here to learn and any pointers/guidance/advice will be taken
onboard and digested.

If I'm wrong, I'm sure someone will tell me!


  #4  
Old July 3rd 03, 09:26 PM
JC Der Koenig
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Posts: n/a
Default How long before aerobics "kicks in"??

This has been studied in-depth, and you're right.

"Mongie" wrote in message
...

Absolute crap. Why can't "all of your energy come from fatty acids that

your
fat stores provide"? More to the point, people on zero carb diets

obviously
can and do manage to exercise intensely.


I'd be interested if you could point me in the direction of just one

person
on a "zero carb" diet who successfully manages to "exercise intensely".

Define "intensely".

I do approx 95 mins "intense" cardio per day (and by "intense" I mean at

the
rate of 22 calories per minute) - my aim is to burn 2000 calories per day.

Completely unintentionally, and due to circumstances, on Monday of last

week
my carb intake was 50g. However, I made a point of hammering the protein
that day to ensure my calorie intake was sufficient.

Tuesday's workout was a disaster..........I got to 670 calories and
*bang*........I hit the proverbial brick wall and I wasn't going anywhere
further.

Conclusion: my lack of carb intake on the previous day had an adverse

effect
on my endeavours to work out.

I hate carbs as much as the next person but I begrudgingly concede (from
personal experience) that they're necessary, nay essential, to be able to
undertake intense cardio activity with any degree of success.

However, I'm here to learn and any pointers/guidance/advice will be taken
onboard and digested.

If I'm wrong, I'm sure someone will tell me!




  #5  
Old July 4th 03, 02:12 AM
Peter Webb
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Posts: n/a
Default How long before aerobics "kicks in"??

I exercise every day for 40 minutes at a rate of 1100 kCals/hr (ie I burn
760 kCals in 40 minutes). Almost the same rate as you, albeit for only half
as much time each day. For me, this is intense exercise (I cycle my pulse
between 160 and 175; at age 47 I am exceeding my theoretical MHR for about
15 of the 40 minutes). This is the same rate of energy expenditure than I
was able to achieve eating normal food.

I do not think that one day of low carbs is a reasonable test. Perhaps your
inability to continue was partially psychological? It takes several days for
most people to go into ketosis, having one low carb day isn't going to
exhaust your glycogen.

I have monitored my aerobic capacity at the same heart rate (which pretty
much corresponds to the same level of perceived effort, to eliminate
psychological bias) for some years on a normal diet, and now for 6 months on
an essentially zero carb diet. My energy output has remained pretty much
constant (1100 kCals/hr), but my ability to run, walk up hill, etc has
dramatically improved, as I am now 20 kgs lighter. The only thing that
didn't markedly improve is my short term 5 minute stress test results.

If you are exercising to lose weight - which is what the OP wanted to do -
there is no question in my mind that you will get much, much better results
on a low or zero carb diet with exercise than you would on a normal carb
diet with exercise. For me, it was three years on a constant 101 kgs, then a
loss of 20 kgs in 6 months on a zero carb diet with no loss of energy,
impact upon my aerobic capacity, or other side effects at all. Talking about
zero carb diets preventing aerobic exercise is counterproductive, as it may
stop people using what is an extremely effective weight loss mechanism.


"Mongie" wrote in message
...

Absolute crap. Why can't "all of your energy come from fatty acids that

your
fat stores provide"? More to the point, people on zero carb diets

obviously
can and do manage to exercise intensely.


I'd be interested if you could point me in the direction of just one

person
on a "zero carb" diet who successfully manages to "exercise intensely".

Define "intensely".

I do approx 95 mins "intense" cardio per day (and by "intense" I mean at

the
rate of 22 calories per minute) - my aim is to burn 2000 calories per day.

Completely unintentionally, and due to circumstances, on Monday of last

week
my carb intake was 50g. However, I made a point of hammering the protein
that day to ensure my calorie intake was sufficient.

Tuesday's workout was a disaster..........I got to 670 calories and
*bang*........I hit the proverbial brick wall and I wasn't going anywhere
further.

Conclusion: my lack of carb intake on the previous day had an adverse

effect
on my endeavours to work out.

I hate carbs as much as the next person but I begrudgingly concede (from
personal experience) that they're necessary, nay essential, to be able to
undertake intense cardio activity with any degree of success.

However, I'm here to learn and any pointers/guidance/advice will be taken
onboard and digested.

If I'm wrong, I'm sure someone will tell me!




  #6  
Old July 4th 03, 04:05 AM
Bob Garrison
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Posts: n/a
Default How long before aerobics "kicks in"??


"Peter Webb" wrote in message
u...
I exercise every day for 40 minutes at a rate of 1100 kCals/hr


How do you know this?


  #7  
Old July 4th 03, 03:03 PM
wringerman
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Posts: n/a
Default How long before aerobics "kicks in"??

"Bob Garrison" wrote in message ...
"Peter Webb" wrote in message
u...
I exercise every day for 40 minutes at a rate of 1100 kCals/hr


How do you know this?



Anyone with half a brain would be able to figure this out, except you
Garrison because you are dumb as a stump. I have been reading your
totally idiotic one liners on a couple of newsgroups and you sound
like a kid that doesn't go out much and has just learned to curse and
swear when his Mommie and Daddie aren't within earshout. You better be
careful because if your folks see what you have been writing on the
computer they will probably give you "time out" and take away your
computer privileges. Then you will have to go back to masturbating
all day long.

Oh I almost forgot, here is a link to the calorie calculator and
figuring a 190 pound person at 13 KM per hour comes out to over 1100
calories per hour. Of course when you read this, you will start
cursing and swearing because you have zero facts to back up anything
you say, and with your very limited vocabulary, won't be able to do
anything else .

http://www.exrx.net/Calculators/Calories.html
  #8  
Old July 6th 03, 01:08 PM
Van Bagnol
external usenet poster
 
Posts: n/a
Default How long before aerobics "kicks in"??

In article ,
"Peter Webb" wrote:

SNIP

To burn more calories, you have to be more active than that. So, you
increase your activity by exercise -- the more intense and/or longer the
duration, the more calories burned.

But when you exercise more intensely, not all of the energy production
will be able to come from fatty acids that your fat stores provide. A
certain percentage of muscle tissue will face shortfalls of the oxygen
it needs, so glucose from the body's glycogen stores is necessary to
"keep the flame going", so to speak, and provide energy to muscle tissue
momentarily starved for oxygen. You can get by with existing body
glycogen for a little while, but you will eventually have to replenish
it -- with carbs.


Absolute crap. Why can't "all of your energy come from fatty acids that your
fat stores provide"? More to the point, people on zero carb diets obviously
can and do manage to exercise intensely.


Not _absolute_ crap, but perhaps I oversimplified it for you. Energy
(ATP) production is _always_ a mixture of several different processes,
some of which cannot come from fat sources.

Not all ATP production is aerobic. A certain percentage is anaerobically
derived even if you are exercising at an "aerobic" level: a modest 230w
power output can still produce ~2 mmol/L of blood lactate -- perhaps not
enough to feel a "burn" but present nonetheless -- indicating anaerobic
glycolytic activity. Furthermore, energy from fatty acids is _only_
aerobic. It has to enter the Krebs/NADH2 cycle directly as acetyl co-A
to produce ATP via oxidative phosphorylation, which requires oxygen.

As exercise intensity increases, and without enough oxygen and enzymatic
machinery for oxidation, the rest of the energy demands must be met more
by the anaerobic processes such as phosphocreatine (which is depleted so
rapidly it really isn't considered in duration exercise) and, of course,
glycolysis. Glycolysis requires glucose, no surprise.

That's why the "percentage of fat" utilization for energy declines with
extreme intensity exercise. It's not that you burn less fat (in fact
it's the opposite), you burn more -- a lot more -- carbohydrate. It
takes 18 times as many glucose molecules 'burned' anaerobically to
provide the same energy as one glucose molecule burned aerobically.

More to the point, I'm not saying people on zero-carb diets can't
exercise intensely. I _am_ saying that they have to temporarily deplete
muscle glycogen to do it, which will have to be replenished before it
runs out. That's why (no surprise either) people bonk.

BTW, glycogen can also be replenished by metabolising protein through
gluconeogenesis. People on zero carb diets do not have zero glucose or zero
glycogen levels.


True, I'd forgotten to mention that certain (C3) amino acids can be
converted to pyruvic acid which is interconvertible to glucose, but I
was addressing the OP's question about 'needing carbs to burn fat' by
explaining that the answer's not quite that simple. I was showing the
manner in which the statement is true, not seeking circumstances where
the statement is false.

Certainly, the most immediate way to replenish carbs is to eat carbs.
And it is possible for the body to synthesize carbs from protein, but
nonetheless, gluconeogenesis is about turning protein into carb, which
was still my point.

The OP was contemplating a low carb diet, but worried that this would make
him stop his exercise regime. It most definitely would not. Low carb diets
are doubly effective if combined with plenty of aerobic exercise.


Actually the OP was already on a low carb diet, and was wondering when
he would start seeing improvements from exercise because he gained 8 lb
since hitting the gym. After you suggested an even _lower_ carb diet, he
was uncertain of your advice because of a differing opinion by another
poster.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
....enjoys - Theatre / Windsurfing / Skydiving / Mountain Biking
....feels - "Parang lumalakad ako sa loob ng paniginip"
....thinks - "An Error is Not a Mistake ... Unless You Refuse to Correct It"
  #9  
Old July 6th 03, 02:28 PM
Peter Webb
external usenet poster
 
Posts: n/a
Default How long before aerobics "kicks in"??

SNIP

More to the point, I'm not saying people on zero-carb diets can't
exercise intensely. I _am_ saying that they have to temporarily deplete
muscle glycogen to do it, which will have to be replenished before it
runs out. That's why (no surprise either) people bonk.


Agreed. Also true if you are NOT on a low carb diet.


Actually the OP was already on a low carb diet, and was wondering when
he would start seeing improvements from exercise because he gained 8 lb
since hitting the gym. After you suggested an even _lower_ carb diet, he
was uncertain of your advice because of a differing opinion by another
poster.

Van


The OP was eating about 100 grams of carbs a day.

It is my belief (based upon my own personal experience) that ketogenic diets
work by simply suppressing appetite. You are not as hungry if you don't eat
carbs. This effect only happens for me on less than about 30-50 grams/day of
carbs. (For me, ketosis kicks in after a few days of 20 grams/day of carbs,
so the hunger suppression does not appear to be directly related to
ketosis).

Unfortunately, if I eat more than 50 grams/day of carbs, there is no
discernable decrease in appetite, and I am simply a guy who goes to the gym
and eats lots of bacon and eggs. With 100 grams/day of carbs and no hunger
suppression, a high protein high fat Atkins style diet could be very
fattening. As I said to the original poster, a diet of 100 grams/day of
carbs limits your food choices without neccessarily providing any weight
control benefit. I simply advised him to try 0 grams/day of carbs instead of
100 to see what happened.

And if you are still reading, dear OP, also take a sugar free fibre
supplement (eg one of the Metamuscil products that is sweetened with
Aspartame) and vitamin pills. My first few weeks on Atkins disproved the old
saying "If you don't eat, you don't ****, and if you don't ****, you die".
On no carbs, you don't ****, but you don't die either ...




  #10  
Old July 7th 03, 01:11 PM
MartinB
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Posts: n/a
Default How long before aerobics "kicks in"??

Yes - OP still here!
And many thanks for all your advice, albeit a bit varied!
I cut my carbs to zero for all of last week - to try and kick start some
weight loss - but still nothing.
Appetite suppression is great though! I'll just have to cope with the keto
breath.....
I'm now back up to approx 20g carbs a day (Atkins style) and will give it a
few weeks to see what gives.
I *am* still tired however, and it feels harder work in the gym these last
few weeks.
My body fat doesn't seem to be reducing either.
I have a hand held cheap meter.
My wife's BF is decreasing nicely - but boo hoo - I've stuck at approx 34%
for the last 2 months.
... not that I think you can trust these things - just thought it may show me
some variations.

I think I may need to cut back the Aerobics a little and up the resistance.
And I've just given up dairy for a week - I think that may be stalling me!
I'm seeing my trainer for my 2 monthly review on Wednesday - let's see what
she says!
(Although she does teach at a gym that says "you must eat carbs to burn
fat!)

And - my body temp seems to have fallen to average 36.6F - could that be a
"lack of carbs" type thing??

Thanks again folks
MartinB






"Peter Webb" wrote in message
u...
SNIP

More to the point, I'm not saying people on zero-carb diets can't
exercise intensely. I _am_ saying that they have to temporarily deplete
muscle glycogen to do it, which will have to be replenished before it
runs out. That's why (no surprise either) people bonk.


Agreed. Also true if you are NOT on a low carb diet.


Actually the OP was already on a low carb diet, and was wondering when
he would start seeing improvements from exercise because he gained 8 lb
since hitting the gym. After you suggested an even _lower_ carb diet, he
was uncertain of your advice because of a differing opinion by another
poster.

Van


The OP was eating about 100 grams of carbs a day.

It is my belief (based upon my own personal experience) that ketogenic

diets
work by simply suppressing appetite. You are not as hungry if you don't

eat
carbs. This effect only happens for me on less than about 30-50 grams/day

of
carbs. (For me, ketosis kicks in after a few days of 20 grams/day of

carbs,
so the hunger suppression does not appear to be directly related to
ketosis).

Unfortunately, if I eat more than 50 grams/day of carbs, there is no
discernable decrease in appetite, and I am simply a guy who goes to the

gym
and eats lots of bacon and eggs. With 100 grams/day of carbs and no hunger
suppression, a high protein high fat Atkins style diet could be very
fattening. As I said to the original poster, a diet of 100 grams/day of
carbs limits your food choices without neccessarily providing any weight
control benefit. I simply advised him to try 0 grams/day of carbs instead

of
100 to see what happened.

And if you are still reading, dear OP, also take a sugar free fibre
supplement (eg one of the Metamuscil products that is sweetened with
Aspartame) and vitamin pills. My first few weeks on Atkins disproved the

old
saying "If you don't eat, you don't ****, and if you don't ****, you die".
On no carbs, you don't ****, but you don't die either ...






 




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