What are LRCers thoughts on using a glycogen depletion marathon training method?

Nope. I still hold my stance on this...Increasing your mileage and long run training will make you more efficient at burning fat. It will also increase your Vo2max, but generally that is linked to improvements in Running Economy (so rather, velocity at Lactate Threshold and velocity at Vo2max) when combined with the appropriate workouts (i.e. intervals at great than 90% max HR). But it's the easy paced mileage and long runs, and tempo runs that are key for fat burning. You go into an 8-mile Tempo run having run an easy 14 miles the day before and you're already in a somewhat depleted state (say you are averaging over 80mpw). If you want to take it to the next level we look at strategic carb depletion, running at very specific HR intensities and the timing of our meals/workouts.Here's the study I cited earlier....http://www.ncbi.nlm.nih.gov/pubmed/23011657

asosdfjaoijf wrote:

S. Canaday wrote:

You're going to be more efficient at burning fat just by doing long runs and running high mileage.

More efficient at running, not at burning fat. Marathon Misconception Numero Uno Sageio.

Ghrelin wrote:

.

Have also read that you can increase glycogen storage by waiting a while to eat after a hard run. This'll slow recovery, though.

where did you read that?

having serious doubts about this claim..

S. Canaday wrote:

Nope. I still hold my stance on this...

Here's the study I cited earlier....

http://www.ncbi.nlm.nih.gov/pubmed/23011657

a study of 3 people? seriously?

are you familiar with the details?

did they do marathon-pace specific work with low-CHO intake?

i'd like to see an explanation of how doing long slow runs with low-CHO intake would help at fat-burning when running at a much higher intensity, i.e., marathon pace

Blitzplay wrote:

Frued wrote:

I think there's also something to be said for mentally conditioning yourself to the experience of glycogen depletion.

Good point! The mental aspect would be very important. After reading the responses to this thread, I am very surprised this strategy does not have a bigger part in most training programs. Why did it drift out of favor over the years? I think there has to be some reason why it is not used as much now. Does anyone know why?

Probably due more to the abundance of the marketing of all the gels, drinks, blocks and shots that are on market now. I suppose that is aimed more toward the slower crowd but it might be creeping into some of the faster runners as well.

glycomagician wrote:

Ghrelin wrote:

.

Have also read that you can increase glycogen storage by waiting a while to eat after a hard run. This'll slow recovery, though.

where did you read that?

having serious doubts about this claim..

Steve Magness tweeted a study about it, but I can't find it at the moment. I might be mistaken.

joho wrote:

Blitzplay wrote:

Good point! The mental aspect would be very important. After reading the responses to this thread, I am very surprised this strategy does not have a bigger part in most training programs. Why did it drift out of favor over the years? I think there has to be some reason why it is not used as much now. Does anyone know why?

Probably due more to the abundance of the marketing of all the gels, drinks, blocks and shots that are on market now. I suppose that is aimed more toward the slower crowd but it might be creeping into some of the faster runners as well.

no, probably because no matter how mentally tough or trained you are, if you are really glycogen depleted, your performance is going to suffer.

it's a physical reality, not a mental state

do you think faster runners don't use gels/carbs in races?

glycomagician wrote:

joho wrote:

Probably due more to the abundance of the marketing of all the gels, drinks, blocks and shots that are on market now. I suppose that is aimed more toward the slower crowd but it might be creeping into some of the faster runners as well.

no, probably because no matter how mentally tough or trained you are, if you are really glycogen depleted, your performance is going to suffer.

it's a physical reality, not a mental state

do you think faster runners don't use gels/carbs in races?

Of course your performance is going to suffer, but to what degree? Considering that IIRC it's impossible to take enough carbs on during the race, everyone's going to be partially depleted the last few miles. Don't you think it makes sense to practice running in that state?

glycomagician wrote:

joho wrote:

Probably due more to the abundance of the marketing of all the gels, drinks, blocks and shots that are on market now. I suppose that is aimed more toward the slower crowd but it might be creeping into some of the faster runners as well.

no, probably because no matter how mentally tough or trained you are, if you are really glycogen depleted, your performance is going to suffer.

it's a physical reality, not a mental state

do you think faster runners don't use gels/carbs in races?

I didn't say faster runner do not use them. I use them in marathons (not that fast). I was referring to the lack of carb depleted training. I rarely take a gel or anything other than water in training.

You can train for the mental aspect of the physical reality. They are connected. Why wait until race day?

As for the pros, I believe Canova has pointed out that his runners takes very little carbs during the race. Usually in the form of a drink. For others, it would be interesting to see how many carbs the pros take compared to your slower runners.

glycomagician wrote:

joho wrote:

Probably due more to the abundance of the marketing of all the gels, drinks, blocks and shots that are on market now. I suppose that is aimed more toward the slower crowd but it might be creeping into some of the faster runners as well.

no, probably because no matter how mentally tough or trained you are, if you are really glycogen depleted, your performance is going to suffer.

it's a physical reality, not a mental state

do you think faster runners don't use gels/carbs in races?

We are not talking about using this strategy in a race. Of course runners are going to take carbs during a race. We are discussing depletion as a simulation of late marathon conditions. Similar to the way as cumulative fatigue is used in marathon training.

I don't think you have to run at MP as you stated earlier to become efficient at burning fat at that given pace. You have to remember the fatigue you will feel going into your long runs during training. You will not have this level of fatigue on marathon day.

To address your last quote: "I'd like to see an explanation of how doing long slow runs with low-CHO intake would help at fat-burning when running at a much higher intensity, ie.e., marathon pace"Check out Phinney at el. for more studies. Yes, I read the full Stellingwerft study...(done with Canada's top marathoners including Reid Coolsaet).Marathon race pace isn't going to be harder than Lactate Threshold intensity ( around 88% Max HR) and likely will be closer to 80-85% max HR intensity. Doing long runs anywhere from 1-2min per mile slower to close to marathon race pace will be a stimulus for increased glycogen sparing and fat utilization that will help you during the race. If you have actually run a marathon (which it sounds like you probably haven't) you'd also know that the brain sucks up a lot of glycogen and when you are on the edge of bonking it changes your thoughts, mood, and neuromuscular coordination.

glycomagician wrote:

S. Canaday wrote:

Nope. I still hold my stance on this...

Here's the study I cited earlier....

http://www.ncbi.nlm.nih.gov/pubmed/23011657

a study of 3 people? seriously?

are you familiar with the details?

did they do marathon-pace specific work with low-CHO intake?

i'd like to see an explanation of how doing long slow runs with low-CHO intake would help at fat-burning when running at a much higher intensity, i.e., marathon pace

glycomagician wrote:

S. Canaday wrote:

Nope. I still hold my stance on this...

Here's the study I cited earlier....

http://www.ncbi.nlm.nih.gov/pubmed/23011657

a study of 3 people? seriously?

are you familiar with the details?

did they do marathon-pace specific work with low-CHO intake?

i'd like to see an explanation of how doing long slow runs with low-CHO intake would help at fat-burning when running at a much higher intensity, i.e., marathon pace

How many Canadian 2.10-2.12 guys do you think there are? 200?

S. Canaday wrote:

If you have actually run a marathon (which it sounds like you probably haven't) you'd also know that the brain sucks up a lot of glycogen and when you are on the edge of bonking it changes your thoughts, mood, and neuromuscular coordination.

marathons? i've run 41. perhaps you should be more cautious with your assumptions?

can you give me a little more specific guidance than "check out Phinney et al" found some studies, but nothing really on point

i didn't mean to be snarky, surely folks here have to realize the limitations of a study with only 3 subjects/participants

No Sage. It won't 'improve fat burning efficiency' that's pseudoscience. Better training increases running efficiency (fuel economy) per se. If what you were saying was true, then high mileage runners would not hit the wall.

Engage a few brain cells instead of just repeating silly dogma. Who metabolizes more fat in a marathon, a guy running 2.03 or a guy running 3.02?

It isn't a contest of who burns the most fat.

I think a better question would be which of your marathoners burn fat more efficiently?

You can train your body to burn a higher percentage of fat running at marathon pace. I didn't say you still won't have to burn a lot of carbs.Post under your real name next time so I know who i'm dealing with here

You say fuel economy. What is the fuel?

From my understanding. Fuel is fat and glycogen. Improved fuel economy is the ability to burn more fat than normal and spare glycogen.

I'm not an expert on whether and by how much certain kinds of training can shift the substrate utilization ratios at marathon pace, but I would like to point out one thing: for most runners (skinny; reasonably fit), running 20-22 miles at ~1min per mile slower than marathon pace WILL NOT fully deplete your glycogen stores.

The ratio of fat to carbs that you burn is proportional to the relative intensity (% VO2 max) that you are running. If you're running a 5k (nearly 100% VO2 max), over 95% of your energy is coming from carbohydrates. But at an easy pace (say 65% of VO2 max), you're only getting about half of your energy from carbs; the rest is from fat. The relationship is not linear; it looks more like this:

http://i.imgur.com/9zvRsas.png

For details on this see these two papers:

Rapoport, B. I., Metabolic Factors Limiting Performance in Marathon Runners. PLoS Computational Biology 2010, 6 (10), e1000960.

Romijn, J. A.; Coyle, E. F.; Sidossis, L. S.; Gastaldelli, A.; Horowitz, J. F.; Endert, E.; Wolfe, R. R., Regulation of endogenous fat and carbohydrate metabolism. The American Journal of Physiology 1993, 265 (3 Pt 1), E380-E391.

But anyways, the bottom line is that most distance runners carry enough carbs to go more like 27-29 miles at an easy pace. If you want to deplete glycogen in training, you must either a) run after fasting, perhaps overnight—many runners do this unintentionally—or b) run at a high percentage of your VO2 max (i.e. faster than just easy or moderate).

One final thing to keep in mind is that you will start to feel the effects of glycogen depletion far before you actually RUN OUT of stored carbs. This is probably because of a central-governor-like pre-emptive pacing strategy, but whatever the reason for it, you'll start to slow down (and, presumably, start to get a carb-sparing training stimulus) when your carb reserves drop below about 30%, IIRC.

Blitzplay wrote:

asosdfjaoijf wrote:

No Sage. It won't 'improve fat burning efficiency' that's pseudoscience. Better training increases running efficiency (fuel economy) per se. If what you were saying was true, then high mileage runners would not hit the wall.

Engage a few brain cells instead of just repeating silly dogma. Who metabolizes more fat in a marathon, a guy running 2.03 or a guy running 3.02?

You say fuel economy. What is the fuel?

From my understanding. Fuel is fat and glycogen. Improved fuel economy is the ability to burn more fat than normal and spare glycogen.

Mythology, that won't go away. When you race a marathon and you pace yourself, if you have carbo loaded well, then you will metabolize a certain percentage of carbs and fat depending on your pace/finish time.

Your economy comes from your fitness. So what you need is economy at around 2 mmols (blood plasma lactate)80% VO2 max or around 70% carbs 30% fats for an elite marathoner, slighly more percentage fat and less percentage carbs for the slower guys.

So you are denying the fact that a well-trained marathoner can burn a higher percentage of fat running a marathon at a certain pace compared to a lesser trained runner (same weight, same marathon pace/time)?When you say "Economy" do you mean, Running Economy (as in O2 consumption)? You're pulling these numbers (2mmol, 80% Vo2max and 70:30 carb:fat ratios), but the ratios and intensities don't just change if you are slower/faster. It's not that cut and dry.It's the whole reason why one trains to "spare" glycogen...A lot does have to do with specific training/conditioning, velocity at LT, velocity at Vo2max and efficient running Economy at Marathon Pace and diet too. But Running Economy (especially around MP) can be tied up in a lot of biomechanics, neuromuscular fine-tuning and improvements in the lactate threshold velocity.The key with running a marathon up to one's potential is to be able to hold a very high percentage of Lactate Threshold velocity for the 26.2 miles. (Even better is when you are well enough trained to have Lactate Threshold velocity be a very high percentage of Vo2max velocity). But fuel is the name of the game in 26.2 and above (or even 13.1 miles if you're running uphill at altitude) and like Canova says we have a tank of oil (Fat) and a tank of sugar (Carbs). We gotta burn both...and we can train and eat in a way that we burn a higher percentage of fat.

asosdfjaoijf wrote:

Blitzplay wrote:

You say fuel economy. What is the fuel?

From my understanding. Fuel is fat and glycogen. Improved fuel economy is the ability to burn more fat than normal and spare glycogen.

Mythology, that won't go away. When you race a marathon and you pace yourself, if you have carbo loaded well, then you will metabolize a certain percentage of carbs and fat depending on your pace/finish time.

Your economy comes from your fitness. So what you need is economy at around 2 mmols (blood plasma lactate)80% VO2 max or around 70% carbs 30% fats for an elite marathoner, slighly more percentage fat and less percentage carbs for the slower guys.