Glycogen Depletion

[DavidL913]

I was thinking of purposely depleting my glycogen in order for fat to burned off. Can someone confirm if my science is correct. If we deplete all the glycogen stores in the muscles of the body, the body will target and burn lipid adipose tissue for energy.

Lets say we keep them depleted after the workout and the AM/afternoon hrs of the next day, then do a refeed on the 2nd day PM. This way we will have energy to train on the 3rd day.

thoughts?

[Znik]

Doesn't work like that which is why a keto diet is no different from a normal diet over time. Low carb/glycogen depletion simply means ketones and Gluconeogenesis (non-carb substance to glucose) takes over the role of carbs/glucose.

The calorie deficit dictates how much fat is burned, everything else just gets compensated for. Glycogen depleted or not makes no difference, the best way to burn fat is to not do anything, glucose and glycogen gets used during high activity (high intensity cardio,weight lifting etc. anything that requires fast/high bursts of energy) as fat provides a slower energy output it has to be compensated by other means of energy or you simply couldn't perform the activity.

Not to mention that glycogen depletion/low carb most likely will cause havoc with your energy, causing NEAT and TDEE to drop. It's for most people counter productive in terms of weight loss and ability to retain lean mass from heavy lifting.

[chokwow]

^ I get what you're saying, but I disagree. It takes a week or so to get your body switched to being a fat burner instead of a carb burner, but depleting glycogen stores most definitely has an effect on fat burning. If you workout with depleted glycogen stores, your body uses ketones and fat. If you eat a diet full of healthy fats, protein, and non usable carbs (i.e. vegetables), then you'll burn more fat than if you're glycogen stores are full. A calorie is not just a calorie. If anything, for optimal fat burning, wait until post-workout to refeed with carbs (i.e. carb back-loading).

[dmacdonal9]

^ I get what you're saying, but I disagree. It takes a week or so to get your body switched to being a fat burner instead of a carb burner, but depleting glycogen stores most definitely has an effect on fat burning. If you workout with depleted glycogen stores, your body uses ketones and fat. If you eat a diet full of healthy fats, protein, and non usable carbs (i.e. vegetables), then you'll burn more fat than if you're glycogen stores are full. A calorie is not just a calorie. If anything, for optimal fat burning, wait until post-workout to refeed with carbs (i.e. carb back-loading).

What evidence do you base this advantage on?

[Znik]

^ I get what you're saying, but I disagree. It takes a week or so to get your body switched to being a fat burner instead of a carb burner, but depleting glycogen stores most definitely has an effect on fat burning. If you workout with depleted glycogen stores, your body uses ketones and fat. If you eat a diet full of healthy fats, protein, and non usable carbs (i.e. vegetables), then you'll burn more fat than if you're glycogen stores are full. A calorie is not just a calorie. If anything, for optimal fat burning, wait until post-workout to refeed with carbs (i.e. carb back-loading).

No, actually read a study on that a while back about marathon cyclists trying to adapt their bodies to primarily use fat instead of glycogen thus being able to go longer before having to refuel. It takes months of proper training to do so and the effect of it was nothing major and it was more beneficial to refeed on carbs often.

Glycogen depletion makes no difference, you require a certain amount of energy (calories) a day, eat below that level and the energy has to come from somewhere which in most cases is from fat stores.
As I said, our primary source of energy is the food we eat and fat stores if you don't eat enough, glycogen/glucose primarily gets used when the fat cannot provide the energy required fast enough or lifting heavy stuff.

You don't magically burn more fat because you are depleted, the net energy balance decides if you drop fat or not. You don't burn less fat over time just because you have stored glycogen. Which again is why Keto vs Carb rich diet makes no effect on amount of fat loss over time.

[DavidL913]

Chris Aceto in one of his fat loss book does mention that when there are carb sources of energy in the body (some stored as glycogen ), it will use that for energy rather than burn fat. Of course, defecit does play a role in fat loss, so some fat will also be used as fuel in a scenario like this. However, my theory is that once depleted, you can most optimally burn more adipose tissue because that the main source of energy. Some muscle may be broken down for energy, but things can be done to mitigate how much is burned.

I will stick to carb cycling, and stay in defecit.

[ironmaniac508]

When I did a mini cut earlier this year I was able to lose body fat consuming 350 grams of carbs per day....I did this because I was in a daily caloric deficit, there is nothing magical about low carb diets or carb cycling. My opinion in regards to anything in regards to fitness is do what you feel is something you can stick with and ultimately get results.

[TheLongRun]

No, actually read a study on that a while back about marathon cyclists trying to adapt their bodies to primarily use fat instead of glycogen thus being able to go longer before having to refuel. It takes months of proper training to do so and the effect of it was nothing major and it was more beneficial to refeed on carbs often.

Not to mention that the rate of aerobic intensity that's performed with these activities is pretty much exclusively dependent on glucose. Fat and ketones simply cannot be used quickly enough. So guess what happens in a glycogen depleted state? Gluconeogenesis from muscle tissue. Awesome.
I wish they had more success with fat adaptation, but unfortunately glucose is king when it comes to intense performance.
And to OP, basically everything is a function of calories. Glycogen depletion won't do anything fancy. Net energy balance will be the sole determinant of fat loss.

[mavajo]

Everybody wants to re-invent the wheel. There's no secret to fat loss, OP. Just consume less energy than your body spends. Beyond influencing the variables in that equation (e.g., reducing energy consumption or increasing energy expenditure), there's nothing you can do to speed up the process. There's no loophole.

[Znik]

Chris Aceto in one of his fat loss book does mention that when there are carb sources of energy in the body (some stored as glycogen ), it will use that for energy rather than burn fat. Of course, defecit does play a role in fat loss, so some fat will also be used as fuel in a scenario like this. However, my theory is that once depleted, you can most optimally burn more adipose tissue because that the main source of energy. Some muscle may be broken down for energy, but things can be done to mitigate how much is burned.

I will stick to carb cycling, and stay in defecit.

The theory is a "good" one, I was playing around with it a lot in my head initially. But I have never found any backing to it, since the body always finds a way to compensate. If you are glycogen depleted and no carb sources in the body it will simply turn to Gluconeogenesis and then you start sacrificing protein to make glucose for whenever fat cannot support the energy requirement which is usually any activity beyond sitting still or LISS. Which would give the same result as simply eating some carbs/having glycogen stores available. There could perhaps be a tiny benefit from increased TEF through Gluconeogenesis, but you are more likely to have a psychological response to reduce NEAT which would negate the effect because of the lack of carbs/free energy.

Personally whenever I get glycogen depleted my energy drops and I reek of ammonia and it can potentially lead to muscle loss if protein intake is low as certain bodily functions only work on glucose and it has to get the glucose from somewhere.

We all wish there was some awesome trick to burn more adipose tissue and faster, but to my knowledge no one has found one yet apart from a simple daily/weekly/monthly deficit.

But one thing glycogen depletion can work for is if you want to achieve Glycogen Supercompensation.

[ironmaniac508]

Not to mention that the rate of aerobic intensity that's performed with these activities is pretty much exclusively dependent on glucose. Fat and ketones simply cannot be used quickly enough. So guess what happens in a glycogen depleted state? Gluconeogenesis from muscle tissue. Awesome.
I wish they had more success with fat adaptation, but unfortunately glucose is king when it comes to intense performance.
And to OP, basically everything is a function of calories. Glycogen depletion won't do anything fancy. Net energy balance will be the sole determinant of fat loss.

Unfortunately there are several posters on this forum who believe that ketones can be used at high intensity activities.

[dmacdonal9]

Unfortunately there are several posters on this forum who believe that ketones can be used at high intensity activities.

Can be used at high intensities? Yes. Can they be used just as optimally as carbs/glycogen? I don't think so. Great explanation here of why:

http://www.alanaragonblog.com/2013/0...dr-jeff-volek/

[morninglory81]

The only way it is more helpful is if you are having difficulty staying in a deficit. High fat, mod protein, low carb, high fiber, is a formula that keeps you satisfied fairly easily, as long as you can control your carb cravings.

The key is the cal deficit.

If you keto carb cycle you will see extream water fluctuations as well.

[ironmaniac508]

Can be used at high intensities? Yes. Can they be used just as optimally as carbs/glycogen? I don't think so. Great explanation here of why:

http://www.alanaragonblog.com/2013/0...dr-jeff-volek/

That's what I meant by my post, people confuse what can be used with what is optimal.