Unfortunately, to burn only fat means using more oxygen to run at the same speed, so keeping up the same speed when CHO is gone would mean running at a greater fractional utilization of max and that is probably not possible unless up to that point you were not really running at a reasonable marathon pace.
Coach Mook wrote:
You could still run at a MP intensity using primarily fat stores for energy. You just would not be able to run as far a distance.
You've got this backwards, Coach. You can run virtually forever relying solely on fat stores, but you won't be able to do so at marathon pace. You'll need to slow down.
from USA, okay thanks Coach Mook. I asked because it seemed like English might not be your first language. No offense intended. Just curious. Guess you may have been foreign born? That's okay -- see Lagat. thanks again.
lol, actually I don't edit my posts, I don't have the patience, just type and send. I have never been a great, typer, speller, and so on anyway.
jtupper wrote:
Unfortunately, to burn only fat means using more oxygen to run at the same speed, so keeping up the same speed when CHO is gone would mean running at a greater fractional utilization of max and that is probably not possible unless up to that point you were not really running at a reasonable marathon pace.
This is kind of what I am trying to figure out here. If you cannot store enough glycogen in your system to finish a marathon what are the training alternatives to fix this problem. Just slow down? Use more fats early to reserve your other energy supplies? How do you train to accomplish these things?
I'd like to give a special thanks to JD for answering the question above, I'm curious what is the fastest intensity that you can run on fat stores? (at different distances say 400m, 1k or distance runs) Would it be similar speed or do fats break down so slowly that it would be pretty close to the same no matter the distance?
and thanks Running Dogg for just repeating what JD said. Are you telling me that you can't run MP pace for 200m with depleted glycogen stores? If so what evidence do you have of this?
jtupper wrote:
Unfortunately, to burn only fat means using more oxygen to run at the same speed, so keeping up the same speed when CHO is gone would mean running at a greater fractional utilization of max and that is probably not possible unless up to that point you were not really running at a reasonable marathon pace.
This is kind of what I am trying to figure out here. If you cannot store enough glycogen in your system to finish a marathon what are the training alternatives to fix this problem. Just slow down? Use more fats early to reserve your other energy supplies? How do you train to accomplish these things?
I'd like to give a special thanks to JD for answering the question above, I'm curious what is the fastest intensity that you can run on fat stores? (at different distances say 400m, 1k or distance runs) Would it be similar speed or do fats break down so slowly that it would be pretty close to the same no matter the distance?
and thanks Running Dogg for just repeating what JD said. Are you telling me that you can't run MP pace for 200m with depleted glycogen stores? If so what evidence do you have of this?
This is kind of what I am trying to figure out here. If you cannot store enough glycogen in your system to finish a marathon what are the training alternatives to fix this problem. Just slow down? Use more fats early to reserve your other energy supplies? How do you train to accomplish these things?
You've got the right idea in thinking that you need to increase the amount of fat burned at X marathon pace to slow the glycogen decline.
Their are a variety of workouts done to accomplish this but they mostly involve running at around 93ish-100% marathon speed. Those are the speeds that seem to alter the percentage of glyc/fat used by increase, as Canova puts it, Aerobic Fat Power.
If you look at the R (respiratory exchange ratio) that is produced during different intensities of running, this will give you the breakdown of CHO and fat used as fuel. If burning only CHO the R value is 1.00 (R is arrived at by dividing VCO2 by VO2 and when using only carbo for fuel you produce 1 molecule of CO2 for every molecule of O2 used in the chemical equation. When burning only fat, the ratio is .70. So looking at a person's R value tells you what is being used as fuel. At rest we all tend to have an R value of about .85, which indicates 50% of each type of fuel. When running easily the R value tends to stay in the .85-.90 range. At typical marathon pace the R is in the area of .92 to .95. When running about threshold pace the R is close to 1.00 (maybe .98 or so; I need to look at some threshold tests and don't have it on the tip of my tongue). Bad news is that you only have about enough stored carbohydrate fuel to make about 17 miles on nothing but carbohydrate (R of 1.00). On the other hand with an R of about .92 you can make it the full 26 miles because the fuel is not all carbohydrate. Anyway, you can figure, if you run with an R of .85, you should be able to make about 34 miles (if you accept 17 as the 100% carbo limit, this suggests twice that far on 50%). I have a table that suggests how far you can get when functioning with various R values. Then there is the matter of taking in some fuel during the run and how much farther you might expect to get when at an R that is higher than the one that won't let you get 26 miles. Naturally the data presented certainly may vary some, but I hope this gives an idea of what runenrs are up against. It certainly should make it a little clear why going too fast leads to bonking before the finish, because you will bonk when reduced to only fat as fuel.
Jack. Looking over your elite schedule their is not one faster long run. Both mens and womens record holders Radcliffe and Kanouchi did some very fast long runs. Where is the specificity of fuel in your schedule?
Coach Mook wrote:
It would be nice to hear of any training ideas that Coach K has on any of the topics that have been brought up on this thread rather than just trying to "knock" or "fix" other posts.
Coach, a quick check back through this thread and others will reveal some of my thoughts on training. If you have a specific question, I would be happy to try to answer that for you too.
Meanwhile I hope you won't begrudge me a place in this discussion just becasue I sometimes disagree with you. I've very much enjoyed reading the posts of jtupper, S.Canaday, yourself, and others. I think I have acted with maturity in accepting your criticisms of some of my ideas. Here's hoping you can do the same when someone offers an opinion contrary to your own.
sjm1368 wrote:
Are you suggesting that even when these runners slow to marathon pace, their bodies are still burning fuel at the accelerated rate "learned" while doing faster paced workouts? I would think that faster paced training would increase the efficiency of the fuel burning process, but not really jack up that rate when the pace slowed. If you are right about this, it is certainly news to me. Can anyone else corroborate?
I'm suggesting that it alters your fuel consumption rate and distribution.
I'll keep it simplistic. We'll ignore protein and lactate in this process for now.
You have a finite amount of glycogen stored in your body. You have enough fat to last a freaking long time.
Once you start running low on Glycogen, more and more fat has to be used. When fat use increases, energy output decreases per unit time. I.e. you've got to slow down.
I don't have the numbers in front of me b/c I've lent out my book/notes with them to a friend, but the basic idea is this:
You want to increase the amount of fat that is contributing at your goal marathon pace.
So if runner A can run 5:30 pace w/ the average distribution of 80%glyc/20%fat and this percentage/pace makes it where he comes to the finish line right when his glyc. supplies are crap. Now, if we take that same runner and through training make it where at 5:30 pace he's burning 77%glyc/23%fat and he has the same glycogen capacity, then it's obvious that he can now run faster because if he ran at 5:30 pace he wouldn't exhaust his stores at the finish line. So now our runner can run at 5:25 pace and have his stores exhausted at the finish line. So he ran a faster marathon.
It's simplistic, but it gets the point across I think.
Now on to faster paced intervals...
When you do what most people call VO2max type intervals your altering fuel consumption rates. At those paces your body knows it doesn't have to worry about running out of energy supply. It just needs to get as much energy as it can before acidosis and other feedback systems tell the energy systems to start "shutting down."
And to answer someone's question, it effects the ENTIRE speed continum.
To illustrate this point, you can clearly see it in lactate measurements. Do a lot of endurance work and generally the amount of lactate at EVERY speed will decrease. Do a lot of interval/fast stuff and the amount of lactate at EVERY speed will increase. Depending on the test you use, it's easy to see. That's why, as a marathoner, you generally use a test periodically to try and get the athlete to be able to cruise at marathon pace at around 1.8-2.0mmol, then have enough anaerobic capacity to be able to crank it up decently high at the end of the test with a fast 1000m or something similar.
I hope that made sense.
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When you say: "Do a lot of endurance work and generally the amount of lactate at EVERY speed will decrease. Do a lot of interval/fast stuff and the amount of lactate at EVERY speed will increase. Depending on the test you use, it's easy to see."
I take your point, but surely the aim of the faster paced training should be to become more efficient at these faster paces also, so that a lower blood lactate concentration can be achieved at the same pace.
I believe training is effective when:
1, blood lactate concentration is lower for the same pace
2, BLC is the same at a faster pace
3, BLC can be maintained at a higher concentration for longer.
#3 has been getting bad press lately,
This used to be refered to as Lactate Tolerance, but since that expression has recently been falling out of favor, the underlying concept has been wrongly discredited.
I am sure that #3 applies even in the Marathon, where the best runners can mantain a high pace and a low BLC for the first 20 miles or so, and then a very fast pace and a higher BLC to the finish.
I believe training is effective when:
1, blood lactate concentration is lower for the same pace
This is far too simplistic/general a statement to make. There can be many reasons why BLa is lower at the same pace, and they do not always imply that the training has been effective (for the race performance in question).
I am sure that #3 applies even in the Marathon, where the best runners can mantain a high pace and a low BLC for the first 20 miles or so, and then a very fast pace and a higher BLC to the finish.
What research/studies are you quoting here with your, 'first 20 miles at low BLa and then a very fast pace [and what does that mean?] and a higher BLa to finish'?
Coach Mook wrote:
and thanks Running Dogg for just repeating what JD said. Are you telling me that you can't run MP pace for 200m with depleted glycogen stores? If so what evidence do you have of this?
I responded after reading your post on the previous page. The reply from jtupper is on a different page than your post. I did not know he had already corrected you. Sorry for duplicating his post.
As I said in my response, you will not be able to maintian MP for any sort of endurance run with delpleted glycogen. Marathoners who have "hit the wall" will verify this for you.
Marathon lactate is 2.3
I did the quick check and I was right. One post had eveidence of training ideas in this thread. Saying that you think Vo2 max training sessions will have a impact on LT pace. Besides that The best information that you have provided has been a disagreement in vocabulary.
I don't have a grudge wih you. I don't care that you disagree. That is a healthy discussion all I said was that it would be nice to hear and training ideas from you. You are quick to point out what you feel is wrong but don't offer any ideas or questions of your own.
So again It would be nice to hear of any training ideas that Coach K has on any of the topics that have been brought up on this thread rather than just trying to "knock" or "fix" other posts.
Running Dogg wrote:
As I said in my response, you will not be able to maintian MP for any sort of endurance run with delpleted glycogen. Marathoners who have "hit the wall" will verify this for you.
Thats your evidence?I also did not say that you had to maintain MP pacee for an endurance run.
2manyCooks wrote:
I believe training is effective when:
1, blood lactate concentration is lower for the same pace
This is far too simplistic/general a statement to make. There can be many reasons why BLa is lower at the same pace, and they do not always imply that the training has been effective (for the race performance in question).
I am sure that #3 applies even in the Marathon, where the best runners can mantain a high pace and a low BLC for the first 20 miles or so, and then a very fast pace and a higher BLC to the finish.
What research/studies are you quoting here with your, 'first 20 miles at low BLa and then a very fast pace [and what does that mean?] and a higher BLa to finish'?
#1 Isn't too simplistic if #s 2 and 3 also apply.
With regard to: 'first 20 miles at low BLa and then a very fast pace [and what does that mean?] and a higher BLa to finish'
I am applying a rational explanation for performances of elite marathon runners who reach 20 miles in well under 1.40 and then run the last 10k in around 29 minutes, or women runners who do similar performances.
Also, how do you explain 10000m runners going under 26.30 in terms of blood lactate concentration?
How about Renato Canova's explanation that they have a very high lactate steady state?
That is the logical explanation for me, that is denied by some.
Last post Makes a lot of since JD. You suggest to keep from "boinking", a person should Run at a pace that keeps the respiratory exchange ratio between .93 and .95 to last the entire marathon.
How do you know what your respiratory exchange ratio is? I would imagaine that this is not something that the average athlete can can figure out. Seems to me you would need some lab equiptment to figure how much oxygen you are uptaking compared to how much CO2 you are expiring. Could the runner during training estimate this off feeling and his breathing rate?
Again how do you train your body to use more fats instead of carbs in the marathon? Do long easy runs actually do this? I would think that it may but might not help at marathon pace. What is your general feeling here?
All good and well but.... wrote:
Marathon lactate is 2.3
For whom?
An average of 100 Mr Average's last 10 marathons?
Coach Mook wrote:
Thats your evidence?
Yep. I'd say that the experiences of thousands (millions?) of marathoners is worthwhile evidence.
Coach Mook wrote:
I also did not say that you had to maintain MP pacee for an endurance run.
Acutally it was me who implied that in the earlier post. You seemed to want to twist that to a discussion of 200 meters, for some reason. I prefer to stick to the original premise, thank you.