LCHF - Low Carb High Fat Diet Ver 2

[Roux 1]

There is another more fundamental reason that muscle glycogen is not stored while riding. During exercise, hormones (e.g., insulin) that promote storage of carbohydrate as glycogen or fatty acids in body fat are suppressed. By contrast, "catabolic" hormones (e.g., epinepherine, cortisol) that mobilize stored fat and glycogen are increased. These hormonal responses make sense because it would be counterproductive to store either carbohydrate or fat when these fuels are needed to supply ATP for muscle contractions. A similar phenomenon occurs at the level of the muscle cell. When the cell is in a low-energy state, i.e., low ATP:ADP ratio, the metabolic pathways involved in the synthesis of glycogen from glucose are suppressed, as are those involved in fat synthesis and storage. At the same time, the pathways that produce ATP from glucose or fatty acids are activated, increasing the energy available to the cell. So, regardless of how much glucose is ingested and absorbed while riding, it will be used to fuel your muscles not stored as glycogen.

I have tested BG during high intensity i.e. 85% upwards, eating an apple and a banana during this session. No spike in BG (4,5mMol/L)..

Soooo, as glikogeen op is werk vet metabolisme nie lekker nie.

[jcza]

There is another more fundamental reason that muscle glycogen is not stored while riding. During exercise, hormones (e.g., insulin) that promote storage of carbohydrate as glycogen or fatty acids in body fat are suppressed. By contrast, "catabolic" hormones (e.g., epinepherine, cortisol) that mobilize stored fat and glycogen are increased. These hormonal responses make sense because it would be counterproductive to store either carbohydrate or fat when these fuels are needed to supply ATP for muscle contractions. A similar phenomenon occurs at the level of the muscle cell. When the cell is in a low-energy state, i.e., low ATP:ADP ratio, the metabolic pathways involved in the synthesis of glycogen from glucose are suppressed, as are those involved in fat synthesis and storage. At the same time, the pathways that produce ATP from glucose or fatty acids are activated, increasing the energy available to the cell. So, regardless of how much glucose is ingested and absorbed while riding, it will be used to fuel your muscles not stored as glycogen.

I have tested BG during high intensity i.e. 85% upwards, eating an apple and a banana during this session. No spike in BG (4,5mMol/L)..

Soooo, as glikogeen op is werk vet metabolisme nie lekker nie.

 

BOOM!! - spot on, fat burns in a carb fueled fire. You need glycogen, however what I have read is that training at low intensity helps the body conserve glycogen and that fat adapted athletes are better at conserving glycogen. Research have also found that elite athletes store more glycogen than non-elite athletes.

[Roux 1]

BOOM!! - spot on, fat burns in a carb fueled fire. You need glycogen, however what I have read is that training at low intensity helps the body conserve glycogen and that fat adapted athletes are better at conserving glycogen. Research have also found that elite athletes store more glycogen than non-elite athletes.

 

Spot on::

We know that riders who are close to fully glycogen depleted bonk, and that riders who do Brevet's(The majority of randonneuring events are classified as "brevets des randonneurs".^[7] In such events, riders follow a course through a series of predetermined "controls" (checkpoints); these are typically a few tens of kilometres apart. Each rider carries a "brevet card" which must be stamped at each control to prove completion. In some events, riders will be asked to supplement this by collecting till receipts in certain places and by answering questions about their surroundings at "information controls", e.g. recording a distance from a milepost. At the end of the event, the brevet card is handed in to the organizers who will then check and certify the results. Riders are expected to keep within minimum and maximum average speed limits. For a typical 200 km brevet, the minimum speed is around 15 km/h and the maximum is 30 km/h. Riders who arrive early at controls will be made to wait before they can carry on!) can essentially ride forever without bonking. That suggests to me that they must either be not touching glycogen at all, or forming and using it constantly.

[htone]

When you run out of glycogen you will bonk yes, and in the worst instance your brain will shut down your body in order to protect itself (the brain) thus ensuring that it has what remains of glycogen for itself.

 

When you become fat adapted, your ability to replenish your glycogen from fat stores becomes more efficient, but from current data (in this group) apparently not efficient enough to keep up with the body's demands for glycogen at high levels of exertion.

 

My contention remains that with enough adaptation we should be able to reach a "tipping point" where the fat metabolism can indeed keep up with this demand, even at maximum continued effort. But I guess this is a little like the "Holy Grail" of low-carbing and the question is probably more around how much time we will need to get there and at what levels of intensity (and for how long) we will need to train to achieve this.

 

I can certainly say from my own efforts that where I used to bonk at almost exactly 90 minutes, I can now ride for much longer (agreed not at max effort) before I get to a point where I can feel a bonk coming on, but by "surfing the bonk" you can allow your fat metabolism to catch up enough to give you more fuel, so what I do is I tap off until I feel the energy coming back and then pick up the pace again. Do this enough times and you start shifting this deeper and deeper into the ride. Again, this is not something that one should do under race conditions, but rather under controlled conditions in a training environment.

 

I hear everyone saying "we tried this" but I guess the point I make (with tongue in cheek at times) is "have we tried hard enough ?". Who knows what we are really capable of ?

 

edit: and what I wanted to say was that one of the keys must be to always ensure that there is some glycogen left in the store...

Edited November 14, 2013 by htone

[htone]

There is another more fundamental reason that muscle glycogen is not stored while riding. During exercise, hormones (e.g., insulin) that promote storage of carbohydrate as glycogen or fatty acids in body fat are suppressed. By contrast, "catabolic" hormones (e.g., epinepherine, cortisol) that mobilize stored fat and glycogen are increased. These hormonal responses make sense because it would be counterproductive to store either carbohydrate or fat when these fuels are needed to supply ATP for muscle contractions. A similar phenomenon occurs at the level of the muscle cell. When the cell is in a low-energy state, i.e., low ATP:ADP ratio, the metabolic pathways involved in the synthesis of glycogen from glucose are suppressed, as are those involved in fat synthesis and storage. At the same time, the pathways that produce ATP from glucose or fatty acids are activated, increasing the energy available to the cell. So, regardless of how much glucose is ingested and absorbed while riding, it will be used to fuel your muscles not stored as glycogen.

I have tested BG during high intensity i.e. 85% upwards, eating an apple and a banana during this session. No spike in BG (4,5mMol/L)..

Soooo, as glikogeen op is werk vet metabolisme nie lekker nie.

 

Roux, also remember that the glycogen in muscles only fuel those muscles, it cannot be shuttled to other muscles or other parts of the body. Once that is used up, the only store for glycogen is the liver, and that supplies all the muscles, organs and the brain, so guess which one of those will override the command centre when the stores are running low

[jcza]

..............

 

But I guess this is a little like the "Holy Grail" of low-carbing and the question is probably more around how much time we will need to get there and at what levels of intensity (and for how long) we will need to train to achieve this.

 

................

 

Nail on the head htone. Exactly what we are searching for. I started in Nov last year and believe me I have tried to race no carb and it ended in tears. I find that I'm able to race on much less that before so maybe I am able to preserve glycogen better.

[davetapson]

Also that under exercise, you are not going to get BG spikes.

 

(Google "glutame translocation".)

Short (and probably oversimplified) explanation:

1. Under conditions of rest, ingestion of carbs causes BG/insulin spike and glutame transports glucose to fat (and you get the other glycogen storage process going on as well - to liver, and marginal amount to muscles.).

2. Under conditions of exercise, glutame transports glucose to muscle. There is no (or in reality, a much reduced) BG spike due to the glucose being quickly shuttled into the muscle cells.

 

So it doesn't really matter what form of sugar you ingest, and if bonking is a risk due to the intensity that you are riding at, then logic says you should be using something high GI. Why restrict avl glucose when you are potentially running short of it?

 

I now use gu's for planned carb intake (after 30 mins, and then every 45mins or as needed) and whatever is lying around for unplanned carb intake.

 

I also believe htone is probably right regarding the 'if you push adaptation far enough, your liver should be able to generate enough carb to support high intensity'.

 

I've given it a go, but for me that's one step too far at the moment and I will stick to carb supplementing during high intensity exercise.

 

<cynicism on>

My own opinion here - treat as you wish:

 

The whole low GI thing is a bit of a scam.

 

If you are exercising, you are not going to get the big BG spikes we think we will get.

 

If you test someone exercising with a low GI supplement, you will get no (read "a reduced") BG spike.

If you test someone exercising with a high GI supplement, you will get no (read "a reduced") BG spike.

 

If you put a graph of the results shown in the low GI study (which is the same as the high GI study) and say "look, use our product and you don't get BG spikes", then I say you are like manufacturers who put "No Cholesterol" on margarine packaging. Misleading the uninformed for marketing purposes.

<cynicism off>

[htone]

Nail on the head htone. Exactly what we are searching for. I started in Nov last year and believe me I have tried to race no carb and it ended in tears. I find that I'm able to race on much less that before so maybe I am able to preserve glycogen better.

SO... let's keep pushing, everyone. One of us is bound to find the answer or the key... or perhaps we just need to doggedly keep pushing the envelope ?

 

Very cool to hear the experiences of new contributors to this thread and I think we can collectively agree that if nothing else, we can indeed ride for longer with less fuel already !

[davetapson]

Nail on the head htone. Exactly what we are searching for. I started in Nov last year and believe me I have tried to race no carb and it ended in tears. I find that I'm able to race on much less that before so maybe I am able to preserve glycogen better.

 

Totally agree.

 

For me cho no longer make or break to complete a race, just a 'top up' for intensity purposes.

 

I'd suggest that it's not just preserve glycogen better, but utilize fat better as well?

[the nerd]

I started LCHF on monday this week and so far so good, felt a little fuzzy yesterday and i couldnt push at gym like normal but otherwise feeling ok.

 

Want to get a Ketone meter today if i can find one at dischem?

[htone]

 

<cynicism on>

My own opinion here - treat as you wish:

 

The whole low GI thing is a bit of a scam.

 

If you are exercising, you are not going to get the big BG spikes we think we will get.

 

If you test someone exercising with a low GI supplement, you will get no (read "a reduced") BG spike.

If you test someone exercising with a high GI supplement, you will get no (read "a reduced") BG spike.

 

If you put a graph of the results shown in the low GI study (which is the same as the high GI study) and say "look, use our product and you don't get BG spikes", then I say you are like manufacturers who put "No Cholesterol" on margarine packaging. Misleading the uninformed for marketing purposes.

<cynicism off>

 

This was indeed a takeaway from Jeroen Swart's talk the other night - the whole low-GI thing is indeed quite pointless. Under exercise, when glycogen is depleted, you want those stores replenished NOW. A low-GI supplement merely prolongs this process, while something like table sugar would probably be a better option in a case of emergency. Two things that assist with the absorption of carbs in the gut / replenishment of glycogen stores are salt and caffeine. Hence the salt content in some energy preparations and this is why cycling and coffee go together so well. He agreed that the best top-up would be a GU type gel. According to JS (and many in the industry) the all time greatest energy replenisher is still Coca-Cola - it contains sugars in almost the perfect combination of fructose : dextrose as well as at the right dilution and with a helping of caffeine with that. I guess that's why, when you bonk, that Coke at the cafe on the corner has always been the lifesaver !

 

The truth is that during exercise your insulin production is practically shut down as your body is using the adrenal hormones to shuttle nutrition to the cells as fast as possible - he also mentioned that if you are carb sensitive or a Type 2 diabetic, to stop using carbs about 45 min before the end of the ride, so that you don't end up with excess carbs when you finish your ride. Of further interest was his debunking of the myth around eating muesli or raisins just before or during a race - some of the contents (like raisins) take up to 24 hours to digest so they will have almost no effect on your carb stores during a race, but because of how your body shuts down blood supply to the gut, these may end up causing major gastric discomfort....

[jcza]

Totally agree.

 

For me cho no longer make or break to complete a race, just a 'top up' for intensity purposes.

 

I'd suggest that it's not just preserve glycogen better, but utilize fat better as well?

 

Through endurance training adaptations and specialized regimens (e.g. fasted low-intensity endurance training), the body can condition type I muscle fibers to improve both fuel utilization efficiency and workload capacity to increase the percentage of fatty acids utilized as fuel, sparing carbohydrate use from all sources.

 

Comes back to training at low HR again. We need to bear in mind that the amount of carb taken during a race is roughly 40gr per hour although I find that I'm able to stretch it to 90 mins.

[htone]

I started LCHF on monday this week and so far so good, felt a little fuzzy yesterday and i couldnt push at gym like normal but otherwise feeling ok.

 

Want to get a Ketone meter today if i can find one at dischem?

 

Welcome and much good luck. What you are feeling is "carb flu" and IF you are feeling this it means that you have restricted your carb intake low enough for your body to start showing withdrawal symptoms. Now just watch out for your body's "junkie mentality" to kick in as it tries to convince you that one more pie or one more sweet won't be bad for you.

 

My advice is to not waste your money on a ketone meter. I have one and I use it once in a blue moon just as a control - the strips for this meter are helluva expensive too. Rather order some ketostix from someone like @flexia (PM her, she's on The Hub) and use that to get you going. A purple indication on that stick shows you that you are in the right zone and that's really all you need to know !

 

Keep us posted on progress and shout if there is anything that you need help with, there is a lot of collective experience and sometimes even wisdom on this thread

[Roux 1]

SO... let's keep pushing, everyone. One of us is bound to find the answer or the key... or perhaps we just need to doggedly keep pushing the envelope ?

 

Very cool to hear the experiences of new contributors to this thread and I think we can collectively agree that if nothing else, we can indeed ride for longer with less fuel already !

 

And harder. There is a lot of power in the word "and"

[davetapson]

This was indeed a takeaway from Jeroen Swart's talk the other night - the whole low-GI thing is indeed quite pointless. Under exercise, when glycogen is depleted, you want those stores replenished NOW. A low-GI supplement merely prolongs this process, while something like table sugar would probably be a better option in a case of emergency. Two things that assist with the absorption of carbs in the gut / replenishment of glycogen stores are salt and caffeine. Hence the salt content in some energy preparations and this is why cycling and coffee go together so well. He agreed that the best top-up would be a GU type gel. According to JS (and many in the industry) the all time greatest energy replenisher is still Coca-Cola - it contains sugars in almost the perfect combination of fructose : dextrose as well as at the right dilution and with a helping of caffeine with that. I guess that's why, when you bonk, that Coke at the cafe on the corner has always been the lifesaver !

 

The truth is that during exercise your insulin production is practically shut down as your body is using the adrenal hormones to shuttle nutrition to the cells as fast as possible - he also mentioned that if you are carb sensitive or a Type 2 diabetic, to stop using carbs about 45 min before the end of the ride, so that you don't end up with excess carbs when you finish your ride. Of further interest was his debunking of the myth around eating muesli or raisins just before or during a race - some of the contents (like raisins) take up to 24 hours to digest so they will have almost no effect on your carb stores during a race, but because of how your body shuts down blood supply to the gut, these may end up causing major gastric discomfort....

 

Interesting.

 

I ran comrades on coke mixed half half with water...

 

edit: ...back in the day when I was young and stupid and didn't know any better...

Edited November 14, 2013 by davetapson

[davetapson]

I love this thread...

 

I've learned so much... even the guys who call you out on stuff you say make you reconsider your beliefs and check that you aren't talking/believing complete BS.

 

It's been pretty damn interesting.

Edited November 14, 2013 by davetapson