Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity [...]
Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.
At most, your brain can run with 75% ketones/25% glucose. Other organs (kidneys, red blood cells, cornea) need about 15-25 grams/carb per day. If you do not get glucose from diet, your body will build it (gluconeogenesis).
Must see if you want to understand/practice keto right:
As far as my research into keto goes eating too much carbs kicks you out of ketosis (duh!) and eating too much protein triggers gluconeogenesis which also kicks you out of ketosis. Which is a shame because I'd be happy to eat fatty steak and fatty pork all the time!
Keto guidelines generally say 30g carbs per day and that's what I'm going to stick to (net carbs; I want to eat avocados!). So typical keto diet should work fine with what you say about carb requirement.
I don't have any particular desire to go all the way to 0 (or some really low number) and if I have some carb budget left I'm happy to get a latte.
Starbucks says grande almond latte has 9g carbs (5g sugars). Perfect to tidy it up to just below 30g/day.
I've been weightlifting for a while and got fitter and stronger but the progress has been slow so I decided to change things up. I read about keto and the more I read the more awesome it seemed.
Since I switched to keto I have an amazing mental clarity. Literally from the moment I open my eyes in the morning I feel lucid (before I'd take me maybe 30 min and maybe a coffee to "wake up"). And I feel lucid all the way until I fall asleep (I don't get tired before falling asleep. Just go to bed, sleep). Nice and steady energy throughout the day.
Also, I feel noticeably better overall. My max strength suffered a little bit (keto can take 1-3 months to adjust) but I'm more energetic throughout the day, mind and body.
Not sure what this other guy will say, but for the vast majority of people it is for major weight loss, not necessarily lifestyle or belief that it is a "superior" health approach. This is my experience from Reddit's keto and loseit communities anyway.
If you do not get glucose from diet, your body will build it (gluconeogenesis).
That is also my knowledge. Therefore, there seems no need for any intake of carbohydrates; So the claim about "needing carbohydrates" is not warranted (about intake, anyway)
I’ve been <20g of carbs per day since February 2016. My athletic performance was impaired for the first 6-8 weeks, but has since increased dramatically.
At low circulating insulin levels, most cells in your body can efficiently metabolize fatty acids. For the minority of cells that cannot, your liver converts protein into sugar by a process known as gluconeogenesis.
It’s very possible to be a performance athlete and eat very low carb.
80m of exercise is enough to deplete muscle glycogen to as-near-zero as makes no difference.
In a sessile starvation state glycogen stops being a meaningful energy source after 2 days, with the majority of it depleted in approximately 8-12 hrs (it's non-linear).
Depending on one's baseline physical activity and what they mean by "half a day," sure, glycogen stores can be reasonably depleted.
That said, glucogenic amino acids can replenish glucose stores, which can ultimately become glycogen. Glycogen remains low only in the context of low-carb and low-total calories, so what glycogen is replenished is soon exhausted.
"Doing keto" implies less than 20g/day on an ongoing basis, at least as I understand it. On top of that, one might have eaten early in the previous day, eaten no breakfast, and be working out about lunch time, which would provide the "at least half a day without carbs of any kind".
It may be that you disagree, but I get the feeling that you ignored the "doing keto" part of my setup, and instead thought that the person in question was eating cake 12.5 hours before the workout. :)
I can achieve 'dark purple' on strips in two to three days without drastic dietary or exercise extremes. This is one of my biggest sticking points with articles that make generalizations about body functions. There are always outlying examples and exceptions.
You probably already know this, but in case other readers don't, the depth of color on keto sticks is NOT a measure of "how deeply in ketosis" you are.
The depth of color indicates how concentrated ketones are in your urine, which is impacted by (1) the amount of ketones your body is producing, and, very importantly, (2) your hydration level (i.e. how diluted your urine is).
For newbies, if the stick is pink AT ALL, congrats, you're in ketosis. Don't make the depth of color a big goal.
A little known fact is that you can induce ketosis while eating carbs. The biochemistry here is clear: You get into ketosis when you oversupply acetyl groups to the TCA cycle. Adding MCT (Medium Chain triglycerides) to your diet will do this.
Comments
Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.
At most, your brain can run with 75% ketones/25% glucose. Other organs (kidneys, red blood cells, cornea) need about 15-25 grams/carb per day. If you do not get glucose from diet, your body will build it (gluconeogenesis).
Must see if you want to understand/practice keto right:
https://www.youtube.com/user/chrismasterjohn/videos
I started a keto diet 2 weeks ago.
As far as my research into keto goes eating too much carbs kicks you out of ketosis (duh!) and eating too much protein triggers gluconeogenesis which also kicks you out of ketosis. Which is a shame because I'd be happy to eat fatty steak and fatty pork all the time!
Keto guidelines generally say 30g carbs per day and that's what I'm going to stick to (net carbs; I want to eat avocados!). So typical keto diet should work fine with what you say about carb requirement.
I don't have any particular desire to go all the way to 0 (or some really low number) and if I have some carb budget left I'm happy to get a latte. Starbucks says grande almond latte has 9g carbs (5g sugars). Perfect to tidy it up to just below 30g/day.
What was your motivation for starting the keto diet?
I've been weightlifting for a while and got fitter and stronger but the progress has been slow so I decided to change things up. I read about keto and the more I read the more awesome it seemed.
Since I switched to keto I have an amazing mental clarity. Literally from the moment I open my eyes in the morning I feel lucid (before I'd take me maybe 30 min and maybe a coffee to "wake up"). And I feel lucid all the way until I fall asleep (I don't get tired before falling asleep. Just go to bed, sleep). Nice and steady energy throughout the day.
Also, I feel noticeably better overall. My max strength suffered a little bit (keto can take 1-3 months to adjust) but I'm more energetic throughout the day, mind and body.
Not sure what this other guy will say, but for the vast majority of people it is for major weight loss, not necessarily lifestyle or belief that it is a "superior" health approach. This is my experience from Reddit's keto and loseit communities anyway.
That is also my knowledge. Therefore, there seems no need for any intake of carbohydrates; So the claim about "needing carbohydrates" is not warranted (about intake, anyway)
Half a day of carb restriction wouldn't meaningfully deplete glycogen stores.
I’ve been <20g of carbs per day since February 2016. My athletic performance was impaired for the first 6-8 weeks, but has since increased dramatically.
At low circulating insulin levels, most cells in your body can efficiently metabolize fatty acids. For the minority of cells that cannot, your liver converts protein into sugar by a process known as gluconeogenesis.
It’s very possible to be a performance athlete and eat very low carb.
80m of exercise is enough to deplete muscle glycogen to as-near-zero as makes no difference.
In a sessile starvation state glycogen stops being a meaningful energy source after 2 days, with the majority of it depleted in approximately 8-12 hrs (it's non-linear).
Depending on one's baseline physical activity and what they mean by "half a day," sure, glycogen stores can be reasonably depleted.
That said, glucogenic amino acids can replenish glucose stores, which can ultimately become glycogen. Glycogen remains low only in the context of low-carb and low-total calories, so what glycogen is replenished is soon exhausted.
...even if you'd already been doing keto on an ongoing basis?
„no carbohydrate intake at all for half a day before“ no way your body was in ketosis.
"Doing keto" implies less than 20g/day on an ongoing basis, at least as I understand it. On top of that, one might have eaten early in the previous day, eaten no breakfast, and be working out about lunch time, which would provide the "at least half a day without carbs of any kind".
It may be that you disagree, but I get the feeling that you ignored the "doing keto" part of my setup, and instead thought that the person in question was eating cake 12.5 hours before the workout. :)
the specific number varies between different people. i'd say <20g is enough to get everybody into ketosis. <50g is enough for some.
It takes about a week of < 20g/carbs a day for the body to go into ketosis. This is born out by buying keto strips and testing your urine.
I can achieve 'dark purple' on strips in two to three days without drastic dietary or exercise extremes. This is one of my biggest sticking points with articles that make generalizations about body functions. There are always outlying examples and exceptions.
You probably already know this, but in case other readers don't, the depth of color on keto sticks is NOT a measure of "how deeply in ketosis" you are.
The depth of color indicates how concentrated ketones are in your urine, which is impacted by (1) the amount of ketones your body is producing, and, very importantly, (2) your hydration level (i.e. how diluted your urine is).
For newbies, if the stick is pink AT ALL, congrats, you're in ketosis. Don't make the depth of color a big goal.
this is not true for all people and urine tests are not considered reliable. I can get into ketosis in a single day of fasting
A little known fact is that you can induce ketosis while eating carbs. The biochemistry here is clear: You get into ketosis when you oversupply acetyl groups to the TCA cycle. Adding MCT (Medium Chain triglycerides) to your diet will do this.
I think this needs a little more explanation. Can you provide that?
Check this out: https://youtu.be/DG79PYeqZ78
It takes 3 days for me to hit ketosis at that carb level.