Burning Fat Calories

[Orange Fish]

I believe the body will continue to metabolize it's own fat and protein stores to replenish the glycogen stores that have been depleted. You don't *have* to eat more to refill your depleted stores, but you'll probably feel like total **** while you're waiting for your energy to come back on its own.

Right. And that's a horrible feeling. So that's why we need to eat during intense exercise and especially after.

You're thinking is mostly correct, though, that optimal weight loss is much more complicated that just "____ intensity will produce the best weight loss." Even though caloric debt is the driving mechanism, there are other factors such as:
1) how much time is available for exercise, and how often?
2) does exercising above a certain intensity force a person to miss out on available exercise time for recovery?
3) does exercising below a certain intensity generate boredom (ie, less fun)?
4) does exercise above a certain intensity make the person want to quit or look for excuses not to exercise (ie, less fun)?
5) high-intensity exercise can promote severe hunger cravings due to glycogen depletion. How much can be withstood before the person starts to increase their calorie intake above their baseline?

I believe that exercising as much as possible, at an intensity that is considered "fun" is the way to make the program stick long enough to achieve the desired results. What that means is highly dependent on the individual, though.

I agree. We need to take into consideration not only the science behind what works for weight loss, but what's going to allow the person to do it for the longest total period of time.

 

[Orange Fish]

I think Ric once said that the ideal fat burning zone was sitting on the couch watching TV as those are the conditions when a person burns the highest fat/glycogen percentages. Works for me. Where's my remote?!

Right, that's the greatest percentage of fat to carbohydrate as a fuel source, but total calories won't be much above your basal metabolic rate, so essentially you're not doing anything good for yourself. Total caloric expenditure is key.

 

[Doctor Morbius]

...

I agree. We need to take into consideration not only the science behind what works for weight loss, but what's going to allow the person to do it for the longest total period of time.

If a person has all day to train they they'll have to spend that time in the (alleged) fat burning zones as there is no way they'll be able to exercise with any real intensity.

However, most people have jobs, families and other obligations that prevent them from "being able to do X for the longest total period of time."

But I agree that a person who can spend 5 hours at 60% - 65% of max heart rate (fat burning zone) will burn more total calories through exercise in a given day than a person who spends 1 1/2 hours at, for example, Tempo pace. But is that practical? Given bang for the buck, I'd take 1 1/2 hours of Tempo pace a day as it isn't so much intensity that a reasonably fit person can't repeat it daily. Combined with a sensible diet, the gains in fitness and leisure time would go far beyond those of spending mucho hours in the (alleged) fat burning zones.

 

[Aaberg]

Where do you get the ~3500kcal expended in one workout? That's not going to happen in a 1 hour high-intensity ride.

I suggest you read my example one more time. You have several questions to my post that are answered if you read it more carefully.

I said "That day you have consumed your 2500kcal, but you have expended ~3500kcal (that day) because of your workout."

Regarding your last point in that paragraph, I NEVER concluded that there was a weight loss corresponding to 1000kcal. There may be a total caloric deficit of 1000kcal due to that workout, but I never said anything about weight loss due to this workout. Weight loss must occur over time, not in one workout.

Well, this brings us closer to what I'm suggesting. You previously stated that "For weight loss, where the calories come from isn't as important as the fact that they're being used." I say it does matter. In my example you would have a calorie deficit of 1000kcal that particular day, but 800kcal would be from glycogen. You agree that the glycogen debt has to be repaid, which brings the possible "sustained" calorie deficit for the day in my example down to 200kcal (which are the calories that came from fat utilization).

Is this assuming we're not eating for those two days?

As suggested read my post again. I wrote: "The next day you eat 2500kcal as usual, but in addition, ..."

Your last four paragraphs are based on a fasting state that I have never suggested, so I have no comments to that.

I don't know if you see my point clearly. As mentioned before, I suggest that where the calories come from does matter. A calorie deficit coming from fat loss during a training ride does not have to be repaid. A calorie deficit coming from glycogen depletion during a training ride has to be repaid. Ergo, you want your calorie debt to be in "fat currency", not "glycogen currency".

As I stated earlier, I'm no expert on this subject. It sounds like you are, but I can still not see clearly why my reasoning is not valid. Especially now that you stated in your previous post that "About the glycogen debt, you're right. It will have to be repaid"

 

[frenchyge]

AND they'll impede the recovery process ... AND their immune system will take a dump. Hardly worth it if you ask me.

Agree. I wasn't advocating that approach, just trying to explain that the body won't remain in a depleted state forever if not "refilled". I guess I was supporting the idea that it's total cals burned, not just fat cals, that contribute to weight loss.

What ever happened to sensible weight loss, Frechyge? Is everyone looking for a gimmick, a magic formula or a McDiet these days?

Hey, I'm a sensible guy. Give me the McFatLoss Value meal, and supersize it.

 

[Orange Fish]

I suggest you read my example one more time. You have several questions to my post that are answered if you read it more carefully.

I said "That day you have consumed your 2500kcal, but you have expended ~3500kcal (that day) because of your workout."

Well, this brings us closer to what I'm suggesting. You previously stated that "For weight loss, where the calories come from isn't as important as the fact that they're being used." I say it does matter. In my example you would have a calorie deficit of 1000kcal that particular day, but 800kcal would be from glycogen. You agree that the glycogen debt has to be repaid, which brings the possible "sustained" calorie deficit for the day in my example down to 200kcal (which are the calories that came from fat utilization).


As suggested read my post again. I wrote: "The next day you eat 2500kcal as usual, but in addition, ..."

Your last four paragraphs are based on a fasting state that I have never suggested, so I have no comments to that.

I don't know if you see my point clearly. As mentioned before, I suggest that where the calories come from does matter. A calorie deficit coming from fat loss during a training ride does not have to be repaid. A calorie deficit coming from glycogen depletion during a training ride has to be repaid. Ergo, you want your calorie debt to be in "fat currency", not "glycogen currency".

As I stated earlier, I'm no expert on this subject. It sounds like you are, but I can still not see clearly why my reasoning is not valid. Especially now that you stated in your previous post that "About the glycogen debt, you're right. It will have to be repaid"

This is getting to be too much. I'd like to focus in on your main reasoning. What exactly are you saying? The bottom line...

I had issues with your 3500kcal being burned by 1 workout. That's just impossible.

 

[Orange Fish]

Well, this brings us closer to what I'm suggesting. You previously stated that "For weight loss, where the calories come from isn't as important as the fact that they're being used." I say it does matter. In my example you would have a calorie deficit of 1000kcal that particular day, but 800kcal would be from glycogen. You agree that the glycogen debt has to be repaid, which brings the possible "sustained" calorie deficit for the day in my example down to 200kcal (which are the calories that came from fat utilization).

No, because you're replacing what you lost. Glycogen replenishment happens quickly post-exercise, especially in the first 2 hours. So essentially you can replace exactly what you lost within a few hours of this 1 hour workout. There SHOULD NOT be a "sustained" calorie deficit because of this glycogen utilization.

I don't know if you see my point clearly. As mentioned before, I suggest that where the calories come from does matter. A calorie deficit coming from fat loss during a training ride does not have to be repaid. A calorie deficit coming from glycogen depletion during a training ride has to be repaid. Ergo, you want your calorie debt to be in "fat currency", not "glycogen currency".

you have to stop thinking as "fat" and "glycogen" currency and realize that calories are calories. If you burn enough calories, you will loose weight - simple as that. If you burn a lot of calories in any given workout, you may have used up a lot of glycogen doing so, but will need to replace those calories in general regardless, and with the appropriate meal, you will replace all of the glycogen anyway, so there's no need to worry about "where" it's coming from, only that it's being used.

 

[Aaberg]

This is getting to be too much. I'd like to focus in on your main reasoning. What exactly are you saying? The bottom line...

Hang in there Orange Fish!! You can do it!

I had issues with your 3500kcal being burned by 1 workout. That's just impossible.

I'm not saying 3500kcal is being burned by 1 workout.

I'll give it another try:

Day 1: You eat 2500kcal, you expend 2500kcal due to normal metabolism.
Day 2: You eat 2500kcal, you expend 2500kcal due to normal metabolism + you have 1000kcal calorie ride. Total calorie expenditure for that day = 3500kcal. Anotherwords: You have expended 3500kcal because of your workout, as opposed to 2500kcal when you don't do any workouts.

Capiche?

 

[Orange Fish]

Hang in there Orange Fish!! You can do it!

I'm not saying 3500kcal is being burned by 1 workout.

I'll give it another try:

Day 1: You eat 2500kcal, you expend 2500kcal due to normal metabolism.
Day 2: You eat 2500kcal, you expend 2500kcal due to normal metabolism + you have 1000kcal calorie ride. Total calorie expenditure for that day = 3500kcal. Anotherwords: You have expended 3500kcal because of your workout, as opposed to 2500kcal when you don't do any workouts.

Capiche?

I don't know how else to explain this to you. What you're thinking is incorrect. I can see where you're trying to go with your thoughts, but they are just simply incorrect.

It simply does not matter where you get the calories from if we're talking about weight loss. Calories are calories and if you look at that equation that I gave you, you'll see that. It's quite simple and you're making it more complicated than it has to be.

As for the fasting state, someone brought that up in the middle of the discussion and I thought we were still discussion that state of feeding.

 

[Orange Fish]

Aaberg, I don't know what kind of proof you're looking for, but it sounds like you're not going to change your mind regardless of what you hear or who says it. I can easily go into all of the biochemistry and physiology behind what you're talking about to show you what's going on and give you the apparent proof you're looking for, but this is not a semester long college course.

#1 You can't estimate how many calories are being burned from fat and carbs because you have no idea how much oxygen is being consumed during this workout. The amounts will vary depending on intensity and especially training status. The more trained the athlete is, the more he/she will use fat as the primary energy source at increasing intensities.
#2 If we're eating a proper diet, our Glycogen levels will be replenished post-exercise, so burning "x" amount of calories and taking in less than that number, will allow us to loose weight whether or not we take those calories from fat or glycogen.

Capiche?

 

[Aaberg]

It simply does not matter where you get the calories from if we're talking about weight loss. Calories are calories and if you look at that equation that I gave you, you'll see that. It's quite simple and you're making it more complicated than it has to be.

Weeell, I see what you're saying also, but...

Maybe you could you help me understanding how many calories I need to replenish after these two different training rides?

1) Moderate intensity ride, fat burned: 400kcal, glycogen depleted: 400kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?

2) High intensity ride, fat burned: 200 kcal, glycogen depleted: 800kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?

As for the fasting state, someone brought that up in the middle of the discussion and I thought we were still discussion that state of feeding.

OK

 

[Orange Fish]

Weeell, I see what you're saying also, but...

Maybe you could you help me understanding how many calories I need to replenish after these two different training rides?

1) Moderate intensity ride, fat burned: 400kcal, glycogen depleted: 400kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?

2) High intensity ride, fat burned: 200 kcal, glycogen depleted: 800kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?


OK

Don't think about how much fat vs. glycogen is used. Instead focus on post-exercise nutrition by consuming high-carbohydrate foods in the first 20 minutes after the workout and in the next 2 hours post-exercise. You should still consume your typical higher-carb, moderate protein, moderate to low fat intake after this 2 hour period so that you can provide enough carbohydrates for your body to recover and still get all of the required macro and micronutrients.

You should consume about 6-10grams of carbohydrate per kilogram body weight in your normal diet for an endurance athlete, while during exercise focus on 30-60g of carbs per hour. After a tough session like that, you should have 1-1.5 grams per kilogram body weight in the 2 hours post-exercise, and continue with your normal routine after that.

This way, you'll get enough carbs to replace what you lost, and will still get enough calories to prevent weight gain or loss (whatever your goal is).

 

[frenchyge]

Weeell, I see what you're saying also, but...

Maybe you could you help me understanding how many calories I need to replenish after these two different training rides?

1) Moderate intensity ride, fat burned: 400kcal, glycogen depleted: 400kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?

2) High intensity ride, fat burned: 200 kcal, glycogen depleted: 800kcal
Necessary glycogen replenishment after ride (i.e. calories consumed) = ?

In case #1, the next 400 cal you consume after your ride will replenish your glycogen. Anything eaten after that will go toward fueling your basal metabolism, and by the end of the day if you haven't eaten as many calories as you have burned, then your body will make up the difference by metabolizing fat or protein from storage.

In case #2, it's the same answer only replace 400 with 800 in the first sentence.

If you don't eat anything after your ride, then you'll feel like **** and your body will metabolize fat or protein from storage to replace the depleted glycogen over time.

 

[Aaberg]

In case #1, the next 400 cal you consume after your ride will replenish your glycogen. Anything eaten after that will go toward fueling your basal metabolism, and by the end of the day if you haven't eaten as many calories as you have burned, then your body will make up the difference by metabolizing fat or protein from storage.

In case #2, it's the same answer only replace 400 with 800 in the first sentence.[/QUOTE]So you "have to" eat more (800kcal extra) when a high percentage of the expended calories come from glycogen, and you have to eat less (only 400kcal extra) when a lower percentage of expended calories come from glycogen.

If you don't eat anything after your ride, then you'll feel like **** and your body will metabolize fat or protein from storage to replace the depleted glycogen over time.

First, I don't know where this argument comes from, I have never stated that you should not eat anything after your ride. On the contrary, I'm saying you should eat after your ride, but you have to eat more when a lot of the expended calories come from glycogen, while you can eat less when a smaller amount of the calories come from glycogen.

The "Calories consumed < Calories expended --> weight loss" equation holds true in both cases, but in the first case the "Calories consumed" must be higher because a lot of glycogen (800kcal) is lost, but in the second case "Calories consumed" can be lower, since less (400kcal) of glycogen is lost.

For most people this is intuitively true. You can exercise for hours on lower intensities without getting a hunger kick, but once you turn up the intensity you deplete you glycogen stores faster, and you get a hunger kick when you come back from your ride.

Second, you don't want your body to break down protein (muscle tissue) to replace depleted glycogen, and if I'm not mistaken, fat can not be converted into glycogen. Ergo, you have to replace the glycogen by eating more food.

We all agree that when you exercise some of the energy comes from fat and some from glycogen. My point (restated in yet another way) is that burned fat does not have to be replenished (you can eat less), while depleted glycogen must be replaced (you have to eat more). Where the expended calories come from does matter.

In most cases it is possible to explain complicated processes in the body in a simple and understandable way, without having to go through a semester long course in biochemistry and physiology.

Orange Fish, I hear your "general" comments like "It simply does not matter where you get the calories from if we're talking about weight loss", "Calories are calories ...", "Don't think about how much fat vs. glycogen is used...", "Calories are calories and if you look at that equation that I gave you, you'll see that.", etc

However, to me, these general comments fail to convince me or make me understand why my reasoning is not true, sorry.

 

[jjjtttggg]

In most cases it is possible to explain complicated processes in the body in a simple and understandable way, without having to go through a semester long course in biochemistry and physiology.

Orange Fish, I hear your "general" comments like "It simply does not matter where you get the calories from if we're talking about weight loss", "Calories are calories ...", "Don't think about how much fat vs. glycogen is used...", "Calories are calories and if you look at that equation that I gave you, you'll see that.", etc

However, to me, these general comments fail to convince me or make me understand why my reasoning is not true, sorry.

As a fascinated lurker, I'll chime in . . .

A, I think F has provided the explanation of what O is saying if you think about it, even in your own terms. The point you don't seem to be considering is that you are constantly burning a mix of Carbs, Fat and Protein, every minute of every day (I don't mean to imply you don't know this. I know that you do, but I think it's an important part of what O has been saying even though he hasn't explicitly mentioned it.) If you're not a TdF rider spending 6+ hours a day on the bike, this background energy burn from just living, working, playing, sleeping, etc. will be much greater than what you can burn in your training. So, after either of the two rides you mention, you are are going to need to consume a comparatively large amount of nutrition. That's F's point: no matter what you do - crazy fasting diets aside - you will consume more than enough carbohydrate to re-stock your glycogen stores, because your going to have to consume calories to fuel your basal load, and your body will use that nutrition preferentially to re-stock your glycogen stores.

Let's use your numbers. Pick whatever target energy deficit you want, say, 750kcal. I've heard that a 3,500kcal total deficit will lead to about a 1lb weight loss. I don't know if that's true or not, but let's use it for now. If it is true, a daily deficit of 750kcal would lead to about 1.5lbs per week net weight loss. I suspect that might sound a bit slow to some, but it seems a healthy rate to me. Just my opinion, but if you try to shed weight much faster, I think your riding will suffer. Now take your high intensity and low intensity 1000kcal ride examples. Add in the 2500 basal load and we get a total daily energy consumption of 3500kcal as you've suggested. Now, we want a 750kcal deficit, so assumming your rides are every day once per day, over the course of the 20+ hours or so after whichever ride your talking about you will need to consume some 2750kcal (I'm assuming you didn't eat anything during the ride. If you did, you'd need to subtract those kcals from this figure). Now, assuming a reasonably balanced diet, this consumption will contain plenty of carbohydrate to repay whatever "glycogen debt" you have built up. Over that total 24 hour period, though, your body will come up 750kcal short and have no choice but to metabolize fat to make up the difference, some of that fat will have been metabolized during the ride, and some of it will be metabolized after the ride. I agree with others who've posted that it's a mistake to think of this many kcals from fat and that many from glycogen, but to be very clear, let's use your examples. In the low intensity case you've given, you'd expect to burn 600kcals of fat during ride and in the high intensity case only 200kcal. Here's the key (stated again, sorry to be redundant): the low "glycogen debt" that you talk about in the low intensity case will mean that relatively little of the rest of the day's nutrition will be spent replacing this glycogen, so that relatively more will be available to fuel basal energy needs, leaving only 150kcals of fat to be consumed after the ride. Conversely, in the high intensity case, relatively more of the day's nutrition will be required to meet the "glycogen debt", so that relatively less will be availale to fuel the energy of just living. The result: 550kcals of fat will need to be burned after the ride to meet the total daily energy need.

So, as O says, it really doesn't matter where your energy comes from during exercise, only that the kcals are burned, because as F says, whatever glycogen stores are consumed will easily be replaced from what you must consume before the next days ride just to stay alive (again, Crazy fasting diets aside).

All of this said, I think the real keys to the intensity v. optimal weight loss argument were mentioned earlier in the thread (was it F?), in terms of recovery ability, and a sustainable "fun" level. Even if O is wrong and you are right, I'd go out of my mind crazy bored silly trying to ride for hours and hours at 60%, never mind the sore ass.

On the flip side, as has also been pointed out already, intense rides for me lead to intense hunger which makes controlled nutrition harder to maintain.

Final thought (long post already, I know, but if you've made this far it can't have been all bad): for me it's ALL about hours in the day. I simply don't have the time available to burn many calories at low intensity, and I don't have the discipline to create an energy deficit by dieting, so for me, when I want drop a few lbs, I ride as hard as I can without breaking myself down to the point of not being able to ride the next day. Seems to work.

Best regards,
J

 

[frenchyge]

So you "have to" eat more (800kcal extra) when a high percentage of the expended calories come from glycogen, and you have to eat less (only 400kcal extra) when a lower percentage of expended calories come from glycogen.

No you don't. It's pretty likely that you're going to consume at least 800 cal in the next day or so, especially since your basal metabolism is 2500 cal in your argument. The point is that the body makes up any caloric deficit from its stores no matter what was burned as Orange Fish has been trying to tell you. That's where the weight loss comes from.

First, I don't know where this argument comes from, I have never stated that you should not eat anything after your ride.

It's not an argument or response to anything you said. It's a further example that no matter what you eat or don't eat, your body will replenish your glycogen supplies from storage, and weight loss will result. You're saying that you have to eat more if you burn more glycogen and this is just an extreme example showing that that statement is not true.

The "Calories consumed < Calories expended --> weight loss" equation holds true in both cases, but in the first case the "Calories consumed" must be higher because a lot of glycogen (800kcal) is lost, but in the second case "Calories consumed" can be lower, since less (400kcal) of glycogen is lost.

Hello? Your body will replenish the glycogen supplies from its own fat storage if it has to. I'm not sure how to say this more clearly.

Orange Fish, I hear your "general" comments like "It simply does not matter where you get the calories from if we're talking about weight loss", "Calories are calories ...", "Don't think about how much fat vs. glycogen is used...", "Calories are calories and if you look at that equation that I gave you, you'll see that.", etc

However, to me, these general comments fail to convince me or make me understand why my reasoning is not true, sorry.

I answered your example cases and you still aren't thinking it through. The answer you seek lies in the fact that the body will simply convert more glycogen from its stores. You don't have to *eat* it, the body will *make* it as part of its normal recovery metabolism.

 

[Aaberg]

Hello? Your body will replenish the glycogen supplies from its own fat storage if it has to. I'm not sure how to say this more clearly.

Hello frenchyge. It is clear enough. The question is, is this true? Don't misunderstand me, I'm open to accepting that it is true. It's just that several poeple on this forum argue that a low carb diet is not good for athletes because you will run into glycogen depletion difficulties.

If your body will replenish glycogen supplies from its own fat storage (or by breaking down protein/mucles), then I accept that where the calories are coming from doesn't matter. It answers my question completely and I rest my case.

I answered your example cases and you still aren't thinking it through. The answer you seek lies in the fact that the body will simply convert more glycogen from its stores. You don't have to *eat* it, the body will *make* it as part of its normal recovery metabolism.

I am thinking it through frenchyge, but I'm afraid I have not been able/willing to accept your truths without having a little debate with you.

I will not push this any further. I accept your statements that "you don't have to *eat*" to fill up your glycogen stores, "the body will *make* it as part of its normal recovery metabolism". I didn't think it was so, but I'll accept it.

 

[frenchyge]

Hello frenchyge. It is clear enough. The question is, is this true? Don't misunderstand me, I'm open to accepting that it is true. It's just that several poeple on this forum argue that a low carb diet is not good for athletes because you will run into glycogen depletion difficulties.

Ok, that's reasonable. Don't get too wrapped up around my "not eating anything" comments, since I'm certainly not advocating that as an approach, but rather using it as a "what if?" to help break your paradigm a little. In your scenarios, if you go for an 800 or 1000 cal ride during the day, then you will certainly eat at least that much at some point in the day. JJJTTTGGG really said it better than I that: your body will use those ingested calories to preferentially replenish the glycogen supplies first. After that, if there are extra ingested calories available then they go to storage. If not, or if there's a deficit, then the body uses storage for fuel until the next meal. Because of the continuous process of burning/ingesting/storing the body will maintain the right balance in the right accounts as long as you're not really killing it everyday (as in athletes and low-carb, as you mention above) or trying to achieve too aggressive a deficit (as in fasting diets). Cheers.

 

[Orange Fish]

I am thinking it through frenchyge, but I'm afraid I have not been able/willing to accept your truths without having a little debate with you.

I will not push this any further. I accept your statements that "you don't have to *eat*" to fill up your glycogen stores, "the body will *make* it as part of its normal recovery metabolism". I didn't think it was so, but I'll accept it.

This is where that part about not eating and being in the fasted state comes in. If you do not eat after your workout, your body will be in this "fasted" state and if you continue to not eat, you'll move into "starvation" mode. In this case, you won't have any calories coming in to maintain your blood glucose levels, and if these aren't maintained the body has to regulate itslef to maintain this level (this is one of the most important things the body can do - to maintain blood glucose levels because blood glucose is the most accessible source of energy to the tissues/cells off the body).
In this case, if you don't eat, then fat and protein will be taken from adipose tissue, intramuscular triglyceride stores, or from muscle protein for example, and will be converted *back* to glucose in order to maintain blood glucose levels.
Basically, the glycerol portion of the fats will be converted (through a long series of steps) to DHAP (dihydroxyacetone phosphate) and eventually to G-6-P (Glucose). Once there is glucose made, it can be shuttled via a GLUT transporter to the blood stream. In the case of protein, the carbon backbone of glucogenic amino acids can be used in a similar way to be converted *back* to glucose to provide the body with the much needed glucose and/or glycogen.
The brain is one of the major users of glucose for energy, so that's why when you bonk you feel tired, irritable, etc. It's because your brain doesn't have enough glucose to work with to perform all of its functions. So because our brains are such an important part of our bodies, one of the main things the body has to worry about is providing it with enough glucose for energy and for cellular processes to occur. Granted, in starvation/fasted/atkins/low-carb mode, our brains can preferentially use ketone bodies (byproducts of metabolism in low-carb diets or during starvation) for energy, but this isn't the best way to go.

I think what the bottom line is here is that regardless of whether or not you eat after the workout, one of two things can happen based on what we've all discussed so far:

#1 If you eat after the workout and eat the next day, you'll replenish the glucose, muscle and liver glycogen that was lost durin the workout. Depending on the intensity, there may have been a net caloric loss of energy that may correspond to a weight loss, but exactly where the calories came from isn't as important as the fact that they're gone.

#2 If you do not eat after the workout, you will stay glycogen depleted, but....
your body will be in this "fasted" state and will have to produce new glycogen and glucose from other sources already in the body via Gluconeogenesis and/or Glycogenesis. This is where it will take fat and/or protein and convert it *back* to Glucose or Glycogen.

So wherever the calories come from, as long as you expend enough of them, you'll see weight loss. The body will work out the rest as far as replacing glycogen or glucose that was lost during the exercise. The body only stores a total of about 350g of carbohydrate as muscle or liver glycogen, which provides us with about 1400 calories. And even if we *completely 100%* depleted ourselves of those 350 grams (and the 10 grams that we have floating around as blood glucose) (*these are all accurate numbers btw*), we would only have to consume 1400 calories from carbs over the next 24+ hours to replenish what we lost, and that's easy to do considering most cyclists consume a relatively high carbohydrate diet anyway.

 

[Doctor Morbius]

Nobody here is going to be able to convince Aaberg that he's dead wrong so let him continue to go out and do his "bonk" rides. Sheesh.

Meanwhile, I'm going to go eat some CARBS and get in a couple hours worth of Tempo today.