FAO And Fasted HIIT Training

[scoobydoo]

I've heard from several different sources that fasted HIIT training is super beneficial to increasing glycogen uptake and insulin sensitivity in the muscles, however it also increases FAO. I am confused because I thought that it was important to limit FAO. If this type of training is so beneficial than why is intermittent fasting or low carb so bad? It seems like they work from the same mechanisms. I know I personally was way leaner and had much lower insulin levels when doing IF and low carb.

 

[Hans]

I've heard from several different sources that fasted HIIT training is super beneficial to increasing glycogen uptake and insulin sensitivity in the muscles, however it also increases FAO. I am confused because I thought that it was important to limit FAO. If this type of training is so beneficial than why is intermittent fasting or low carb so bad? It seems like they work from the same mechanisms. I know I personally was way leaner and had much lower insulin levels when doing IF and low carb.

FAO is not bad. It's only bad when it interferes with glucose oxidation. In a compromised state, FAO is increased to compensate for reduced glucose oxidation and incomplete beta-oxidation takes place. This leads to more ROS, more mitochondrial dysfunction and even less glucose oxidation. Glycolysis becomes upregulated and wastes glucose to lactate to compensate for the drop in ATP production.

The question is why do cellular function go wrong and why do glucose oxidation stop. Most of the time it's because of damage to the electron transport chain and complex I, which uses NADH. Once complex I expression reduces, ATP production drops. Now fatty acid oxidation has to increase to produce FADH2 for complex II, bypassing complex I. Excess lipolysis and beta-oxidation in a state of adequate glucose is wrong, but elevated lipolysis and beta-oxidation in a state of low glucose, is fine.

HIIT uses glucose and fats as a fuel source. Low intensity cardio uses mostly fat as fuel. This chronic use of fat increases lipolysis and fatty acid oxidation long term which interferes with glucose oxidation. HIIT does not cause this.

 

[scoobydoo]

FAO is not bad. It's only bad when it interferes with glucose oxidation. In a compromised state, FAO is increased to compensate for reduced glucose oxidation and incomplete beta-oxidation takes place. This leads to more ROS, more mitochondrial dysfunction and even less glucose oxidation. Glycolysis becomes upregulated and wastes glucose to lactate to compensate for the drop in ATP production.

The question is why do cellular function go wrong and why do glucose oxidation stop. Most of the time it's because of damage to the electron transport chain and complex I, which uses NADH. Once complex I expression reduces, ATP production drops. Now fatty acid oxidation has to increase to produce FADH2 for complex II, bypassing complex I. Excess lipolysis and beta-oxidation in a state of adequate glucose is wrong, but elevated lipolysis and beta-oxidation in a state of low glucose, is fine.

HIIT uses glucose and fats as a fuel source. Low intensity cardio uses mostly fat as fuel. This chronic use of fat increases lipolysis and fatty acid oxidation long term which interferes with glucose oxidation. HIIT does not cause this.

So then can’t low carb diets be ok if done right and actually support this metabolic flexibility? For instance eating keto in morning and then refeed with carbs at night after workout?

 

[Hans]

So then can’t low carb diets be ok if done right and actually support this metabolic flexibility? For instance eating keto in morning and then refeed with carbs at night after workout?

Well carbs are great against stress and our carb demands increase during stress. Cortisol is the highest in the morning and we tend to stress the most early in the day as well.
But if your life is generally low stress, low carb am and high carb pm should be fine.

 

[Vinny]

FAO is not bad. It's only bad when it interferes with glucose oxidation. In a compromised state, FAO is increased to compensate for reduced glucose oxidation and incomplete beta-oxidation takes place. This leads to more ROS, more mitochondrial dysfunction and even less glucose oxidation. Glycolysis becomes upregulated and wastes glucose to lactate to compensate for the drop in ATP production.

The question is why do cellular function go wrong and why do glucose oxidation stop. Most of the time it's because of damage to the electron transport chain and complex I, which uses NADH. Once complex I expression reduces, ATP production drops. Now fatty acid oxidation has to increase to produce FADH2 for complex II, bypassing complex I. Excess lipolysis and beta-oxidation in a state of adequate glucose is wrong, but elevated lipolysis and beta-oxidation in a state of low glucose, is fine.

HIIT uses glucose and fats as a fuel source. Low intensity cardio uses mostly fat as fuel. This chronic use of fat increases lipolysis and fatty acid oxidation long term which interferes with glucose oxidation. HIIT does not cause this.

Am not getting into the high science yet, therefore will ask this way:
Will HIIT restore the glucose oxidation (forever and in all cases)?

 

[Hans]

Am not getting into the high science yet, therefore will ask this way:
Will HIIT restore the glucose oxidation (forever and in all cases)?

I don't think so no. It can overtime improve enzymatic function and increase mitochondrial biogenesis, but there might be stubborn cases where it won't improve glucose oxidation greatly. For instance, in some cases, one might have to rely on HIIT for that boosting in insulin sensitivity.

 

[rei]

low carb IF/fasting will lead to increased mitochondrial turnover and regeneration. Once you have functional mitochondria it is not hard to kick the body over to normal glucose oxidation using RP's advice. While in a glycolytic metabolic syndrome state a large carb intake will usually only cause stress, hyperinsulinemia and weight gain.

 

[Zigzag]

low carb/IF/fasting will lead to increased mitochondrial turnover and regeneration. Once you have functional mitochondria it is not hard to kick the body over to normal glucose oxidation using RP's advice. While in a glycolytic metabolic syndrome state a large carb intake will usually only cause stress, hyperinsulinemia and weight gain.

Very unpopular opinion in this forum.

 

[Vinny]

low carb/IF/fasting will lead to increased mitochondrial turnover and regeneration. Once you have functional mitochondria it is not hard to kick the body over to normal glucose oxidation using RP's advice. While in a glycolytic metabolic syndrome state a large carb intake will usually only cause stress, hyperinsulinemia and weight gain.

I wish this is true, because I`ve got no idea how to fix myself another way. Do you know the mechanism behind it? Are there any studies or anecdotes supporting it? Are you aware for a well established approach, like step-by-step sort of? (sorry for asking so much)
Thanks

 

[rei]

Yes some argue you can also achieve it by extremely strict diets, i have not seen evidence about it except the old studies on rice and carnivore anecdotes, but the IF/fasting route has almost universal success rate initially (even in published case reports Therapeutic use of intermittent fasting for people with type 2 diabetes as an alternative to insulin ). The problem is that for a majority of people when they find something that works they stay with it. When the whole idea is that it is a stressful intervention which restores balance, and it is crucial to try and reintroduce carbs to escape the stress in the long run.

When you can tolerate 3 day fasting without much discomfort you are healed and ready to start increasing the sugars. Then carbs. But most importantly, learn to listen to your body and don't stuff in more than you crave, fats, protein and sugar all have different feeling. This all comes almost naturally when fasting and breaking the fast is done with care.

 

[Vinny]

When the whole idea is that it is a stressful intervention which restores balance, and it is crucial to try and reintroduce carbs to escape the stress in the long run.

When you can tolerate 3 day fasting without much discomfort you are ready to start increasing the sugars. Then carbs. But most importantly, learn to listen to your body and don't stuff in more than you crave. This all comes almost naturally when fasting and breaking the fast is done with care.

Noted.

 

[Zigzag]

IF, slight caloric deficit and 3 days fasts have done nothing to me. Hell I combined it with yohimbine and HIIT/weight training to get as much adrenaline and FFA release as possible (I thought that excessive lipolysis was actually a good thing). After a couple of months results were: 0 weight loss, cold hands 24/7 and I'm pretty sure my glucose metabolism became much worse as well.

 

[rei]

Today i found a recent (feb 18) study which talks about this IF->mitochondrial biogenesis link

Gut Microbiota Mediates Intermittent-fasting Alleviation Of Diabetes-induced Cognitive Impairment

zigzag: the idea is to eat ad lib between IF periods. You prevent it from working by running caloric deficit as the body never gets to the rebuilding phase. Coffee also helps greatly, it virtually eliminates all cravings if taken when hungry.

 

[Zigzag]

Today i found a recent (feb 18) study which talks about this IF->mitochondrial biogenesis link

Gut Microbiota Mediates Intermittent-fasting Alleviation Of Diabetes-induced Cognitive Impairment

Ignoring the results, those studies should be done on humans not mice.

 

[Vinny]

IF, slight caloric deficit and 3 days fasts have done nothing to me. Hell I combined it with yohimbine and HIIT/weight training to get as much adrenaline and FFA release as possible (I thought that excessive lipolysis was actually a good thing). After a couple of months results were: 0 weight loss, cold hands 24/7 and I'm pretty sure my glucose metabolism became much worse as well.

If you can,t lose fat on fasting, then .... you,re probably not diabetic (which is good, btw) uh?

 

[Zigzag]

If you can,t lose fat on fasting, then .... you,re probably not diabetic (which is good, btw) uh?

I'm not sure it works that way.