Question for people who actually know about Ketosis.

[migeru29]

Just quick question, simple question but probably not easy to answer.
Does ketones just turn on and off automatically? Or it is a lot more complex?
My understanding is that once the body cannot find carbs then it does start burning ketones. In Keto that's why you eat 50 g max of carbs so once you use them all (rather quickly) you can start burning ketones.
The reason I'm asking is because I feel better during the morning if im fasting/ketosis state at work, but during exercise I definitely feel better on glucose.

So let me know if this scenario does happen in real life.

6pm I eat a combination of high fat/moderate carbs (about 150g of carbs), I exercise around 8pm and burn around 300 calories. Does this mean that I my carbs will be depleted and after my exercise session I will be on Ketosis again?
Then arond 11pm (before sleep) a little bit of protein and fat. Next day I start work at 8am and fast for 16 hours, so i guess i will be on ketosis all this time? Then I eat again moderate carbs around 5 and this process will keep working as I described? Please let me know if is as simple as this.

 

[Literally Bricked]

It isn’t on or off. It takes about three days.

The amount of carbohydrate restriction required to induce a state of ketosis is variable and depends on activity level, insulin sensitivity, genetics, age and other factors but ketosis will usually occur when consuming less than 50 grams of carbohydrates per day for at least three days.

 

[migeru29]

It isn’t on or off. It takes about three days.

The amount of carbohydrate restriction required to induce a state of ketosis is variable and depends on activity level, insulin sensitivity, genetics, age and other factors but ketosis will usually occur when consuming less than 50 grams of carbohydrates per day for at least three days.

Ok thanks. But can you help me to grasp the following scenario:

Ok I do Less than 50 grams a day for a week and I start the state of ketosis.
One day I decided to eat 200 grams of carbs and 3 hours later I exercise and burn 400 calories. What did I used ketones or glucose? If it was glucose then didn't I repleted those 200 calories of carbs? If I did burn all the carbs indeed then why doesn't ketosis turns on? Why am I using as a fuel at that point? Protein?

 

[Literally Bricked]

Ok thanks. But can you help me to grasp the following scenario:

Ok I do Less than 50 grams a day for a week and I start the state of ketosis.
One day I decided to eat 200 grams of carbs and 3 hours later I exercise and burn 400 calories. What did I used ketones or glucose? If it was glucose then didn't I repleted those 200 calories of carbs? If I did burn all the carbs indeed then why doesn't ketosis turns on? Why am I using as a fuel at that point? Protein?

You will use glucose first as it is immediately available. Carbs are made up of things like glucose and fructose.

Whenever the need for energy increases and carbohydrates aren’t available to meet that demand, the body starts increasing its ketone levels. The body prefers to use sugar as its primary fuel source — especially if plenty of carbs and protein are provided by the diet.

 

[Robocok]

Glucose is stored in the muscle and allows the muscle to hold more water. This is partly the reason why people lose so much weight in the first few weeks of a keto or low carb diet. You're depleting the glucose stores and shedding water weight.

Arnold Schwarzenegger and other old school bodybuilders used to have white cake and wine the day before a contest for this reason. It would cause their muscles to swell up with water after they'd replenish their glycogen stores.

Like the other guy alluded, you don't instantly go into ketosis as soon as you stop eating carbs. Your body will first drain the glycogen stores in your muscles. People who practice keto are more efficient at it and will go into keto more quickly and easily. If you've never truly practiced keto, it will take you longer the first time and the process can be difficult and stressful. You may experience what's known as the 'keto flu'.

 

[Grenz]

Ok thanks. But can you help me to grasp the following scenario:

Ok I do Less than 50 grams a day for a week and I start the state of ketosis.
One day I decided to eat 200 grams of carbs and 3 hours later I exercise and burn 400 calories. What did I used ketones or glucose? If it was glucose then didn't I repleted those 200 calories of carbs? If I did burn all the carbs indeed then why doesn't ketosis turns on? Why am I using as a fuel at that point? Protein?

1. Even if you went completely net carb zero (meaning eating pretty much only leafy vegetables, fat and protein) it would still take your body 3-5 days to get into ketosis.

2. Of you were in ketosis for 100 years and you ate a chocolate bar, your body would immediately switch to running on carbs and it would take you 3-5 days until your in ketosis again.

In my experience, a lot less than a chocolate bar was enough to knock me out of ketosis. That’s one of the reasons the diet sucks imo, it’s super easy to get out of ketosis and takes days to get back into it. Plus it sucks donkey balls for anything other than losing fat (and simply cutting calories will give you the same benefit once you factor in loss of water retention) and endurance sports like long distance running.

 

[migeru29]

1. Even if you went completely net carb zero (meaning eating pretty much only leafy vegetables, fat and protein) it would still take your body 3-5 days to get into ketosis.

2. Of you were in ketosis for 100 years and you ate a chocolate bar, your body would immediately switch to running on carbs and it would take you 3-5 days until your in ketosis again.

In my experience, a lot less than a chocolate bar was enough to knock me out of ketosis. That’s one of the reasons the diet sucks imo, it’s super easy to get out of ketosis and takes days to get back into it. Plus it sucks donkey balls for anything other than losing fat (and simply cutting calories will give you the same benefit once you factor in loss of water retention) and endurance sports like long distance running.

Actually I'm more interested in the other benefits that ketosis can provide. It appears that it is more than most another source of fuel. It has some mental benefits as well.

In regards health I really think that one of the best diets out there is the peleo diet. You don't need to be in ketosis but the carbs are just unrefined, grain free from natural source. No dairy which I think is something good. No processed food including meats. I think this diet is very underrated

 

[wufabufa]

2. Of you were in ketosis for 100 years and you ate a chocolate bar, your body would immediately switch to running on carbs and it would take you 3-5 days until your in ketosis again.

I don't really agree with this. Once you're truly fat adapted and you've built those path ways that allow your body to use fat as fuel efficiently, jumping back into a ketotic state should be quicker, especially if you're starting from a completely depleted state.

What you're describing would also be dose dependent. 175lb pound athlete is fully topped up glycogen stores at about 500 grams between his liver and muscle tissue which is approximately 2200 calories worth. One candy bar wouldn't even come close to filling up your stores. For sure it will kick you out of ketosis, I'm not disputing that.

Starting from a pure zero carb state of ketosis, you could eat a king sized Snickers bar at noon, do a really hard glycolytic activity like lifting, sprinting, or HIIT at 2pm and be in ketosis by that evening having blazed through those sugars during your workout. It would probably take you a few days of eating tons starchy, sugar laden foods while avoiding exercise that relies on heavily on glucose, to fully saturate your body with glycogen. Fully topped, yes it would take a few days to burn through that providing you've also ingested other fuel sources (proteins and fats) along with those carbohydrates. Maybe quicker if you plan on only running on carbohydrate and no other macros. I guess you could eat 10 cups of white rice to top up your stores, fast, and do some heavy exercise......you'd back into ketosis within 2 days if that were the case.

 

[Grenz]

I don't really agree with this. Once you're truly fat adapted and you've built those path ways that allow your body to use fat as fuel efficiently, jumping back into a ketotic state should be quicker, especially if you're starting from a completely depleted state.

What you're describing would also be dose dependent. 175lb pound athlete is fully topped up glycogen stores at about 500 grams between his liver and muscle tissue which is approximately 2200 calories worth. One candy bar wouldn't even come close to filling up your stores. For sure it will kick you out of ketosis, I'm not disputing that.

Starting from a pure zero carb state of ketosis, you could eat a king sized Snickers bar at noon, do a really hard glycolytic activity like lifting, sprinting, or HIIT at 2pm and be in ketosis by that evening having blazed through those sugars during your workout. It would probably take you a few days of eating tons starchy, sugar laden foods while avoiding exercise that relies on heavily on glucose, to fully saturate your body with glycogen. Fully topped, yes it would take a few days to burn through that providing you've also ingested other fuel sources (proteins and fats) along with those carbohydrates. Maybe quicker if you plan on only running on carbohydrate and no other macros. I guess you could eat 10 cups of white rice to top up your stores, fast, and do some heavy exercise......you'd back into ketosis within 2 days if that were the case.

You’re probably right, but I think the above is true assuming someone’s on real keto, as opposed to a modified low carb diet, which is basically what almost everyone not on therapeutic keto is on.

 

[Grozer]

I don't really agree with this. Once you're truly fat adapted and you've built those path ways that allow your body to use fat as fuel efficiently, jumping back into a ketotic state should be quicker, especially if you're starting from a completely depleted state.

What you're describing would also be dose dependent. 175lb pound athlete is fully topped up glycogen stores at about 500 grams between his liver and muscle tissue which is approximately 2200 calories worth. One candy bar wouldn't even come close to filling up your stores. For sure it will kick you out of ketosis, I'm not disputing that.

Starting from a pure zero carb state of ketosis, you could eat a king sized Snickers bar at noon, do a really hard glycolytic activity like lifting, sprinting, or HIIT at 2pm and be in ketosis by that evening having blazed through those sugars during your workout. It would probably take you a few days of eating tons starchy, sugar laden foods while avoiding exercise that relies on heavily on glucose, to fully saturate your body with glycogen. Fully topped, yes it would take a few days to burn through that providing you've also ingested other fuel sources (proteins and fats) along with those carbohydrates. Maybe quicker if you plan on only running on carbohydrate and no other macros. I guess you could eat 10 cups of white rice to top up your stores, fast, and do some heavy exercise......you'd back into ketosis within 2 days if that were the case.

Person that knows about keto spotted.

 

[Sherdog Oliver]

Sounds ike a waste of time. A lifetime of excercise and good food is the way to go.

 

[therealdope]

I'm going to draw everyone's attention to a couple of points that address errors that are routinely thrown around in these threads, and other nutrition and fitness discussions.

1. You don't exclusively use any one form of metabolism/energy pathway, at any one time. When you have glycogen and glucose available, you will primarily use it as a source of fuel. That doesn't mean you use zero stored fats or free fatty acids. As you deplete available glucose and glycogen you use more FFAs and stored fats. The idea that you depleted all glycogen/glucose to get to 'fat burning' is not correct. The idea that you are not burning fats when you are primarily using glucose, is incorrect.

2. An elite trained cross country skier (let's just go with XC skiing as it's the sport with athletes that can produce the most watts per unit body weight for sustained periods of time --- 20mins or higher) can burn through most of their glycogen stores in 60-90mins. At that point they either take in simple sugars or start to use much more FFAs and stored fat, to produce Watts. The way you get to using fats, fastest, is by sustained sub-aerobic threshold (AT) efforts --- this is a fact.

3. Doing HIIT and power is not the most efficient way to 'burn fat'. The idea that HIIT is required, or the best way, to burn fat is something that gets thrown around (a lot) but there is no rationale for this. Sub-AT efforts, sustained, are the way to burn the most calories and to get to substantial use of fat for energy.

Now there is an important flip-side to #3 above. Athletes that have the highest watts/kg/min sustained conditioning do 30% HIIT and power training because to ride a bike fast or to run fast, takes a lot of speed. THis is why you find even 5,000/10,000m runners doing what looks like sprinting workouts. To run fast, you must train speed. I don't know if this is the the reason that I see "you have to train power and do HIIT to burn fat", but that statement is misleading. To 'burn fat' you need oxygen, not anaerobic energy systems. You'll know you're burning fat when you are expelling the most carbon dioxide, per minute, sustained. That is exactly where metabolised fat ends up -- CO2. To burn the most fat, you want sustained sub-AT efforts that use as much oxygen as possible. To produce the most watts, sustained, you'll need to train speed power, but the actual activity that consumes the most fat is the ability to sustain power (watts) with sub-AT efforts. If you want to end a fat burning session early, throw in threshold power efforts.

 

[DrTrouble]

What is sub AT?

 

[therealdope]

What is sub AT?

Sub Anaerobic Threshold (aka Threshold power).

 

[DrTrouble]

Sub Anaerobic Threshold (aka Threshold power).

So basically it's aerobic?

 

[therealdope]

So basically it's aerobic?

That's right. It's the maximum work rate relying on the aerobic pathway. Aerobic, being only way you use fats to produce energy.

 

[therealdope]

Exogenous ketones are popular with top teams in pro cycling. Here is a pretty good article with input from several sources including teh developer of ketone esters.

https://www.cyclingnews.com/features/understanding-ketones-what-does-the-wonder-drink-actually-do/

 

[alexcool2020]

I think I'll try this Ketosis diet.