I've been a runner for 9 years and the last 2 1/2 years, I've been doing intermittent fasting for 16 hours. Running on a fasted state improved my performance considerably. My HM had come down from 1:45-1:35. 10k had also changed from 48-43. I do all my runs on a fasted state and the maximum distance I ran was 32km. I never had issues with recovery. During my peak training, I ran 6 days a week with a weekly mileage of 100+km.
Wow, this video is subjective. This is about 2 papers, and there are many more that would echo the same opinion. But what about all the scientific literature that supports fasted training. What about the benefits of being "fat adapted". Considering the majority of people are exercising and training (and a lot even racing) at a level at which using fat as an energy source is more stable, I find it very strange that such a subjective view is being presented. Right out of the Ancel Keys playbook.
Why are we hearing nothing about fat as a fuel. Which is what IF is about. Aerobic level exercise will burn mostly fat. IF is not just about reducing calorie input. It is about reducing insulin production to allow more fat burning.
Low insulin levels along with a well published finding that there is a significant increase in human growth Hormone! No mention of these positive factors and how the hgh production may prevent muscle wasting
I do a 10 hour eating window for IF 8a-6p and it gives my body time to fully digest before sleeping. It improves my sleep quality and keeps me from overeating. If I do run in the morning before eating, I’ll always keep it in zone 2 since I’m essentially glycogen depleted in that state. I do my hard runs in the afternoon a couple hours after breakfast and then have a healthy lunch and dinner to aid recovery. It’s been working
I did my first 15k fasted yesterday and I had no noticeable energy loss and it was actually my fastest time yet! I was however fasting before I started training running and have never had an affinity or need for food in the morning.
It’s very clear Coach Parry knows a lot about running, but very little about nutrition and metabolism. What she says about how the body reacts to IF is totally wrong. She stumbles through what she thinks and mentions insulin not once. Managing insulin levels by eating low carb and IF is key to good short and long term health.
The video doesn't talk about the use of salt to increase the use of energy into the bloodstream. Also doesn't talk about are the subjects long term IF or newbies. Long term have taught the body to use fat reserves as an energy source.
No mention of sodium plus it will take at least a month to get used to not eating 3 meals a day, so that you metabolically switch to using your fat stores of which you have plenty. I have found since fasting that my running has improved lost the extra weight and feel more energetic.
IF, training in a fasted state, cutting out carbs, KETO diet; they improve you as a runner. Ever heard of Mark Sissen, Bruce Fordyce, Dr Phil Mafatone all very respected people who have achieved and follow fasting lifestyle. Shauna and crew know very little abt nutrition clearly.
We all naturally intermittently fast, it's called night time! Unless you're eating till midnight then eating again at 6am, you're doing a daily prolonged fast. Some foods can take many hours to fully digest, I think we're fine doing a morning run before breakfast! If you can't, it means you are probably pretty insulin resistant and you'd actually benefit from fasting longer.
How do you know the cortisol etc will increase from day to day to day? The studies looked at a 24hr period. You cant determines what happens after a few weeks. Sorry
Very interesting. Is there any indication of the exercise intensity ? There are historical examples of intermittent fasting - Van Aaken's school being one, the Swedish / Ron Hill carbo-bleed-then-load being another - but they'd combine fasting/low carb phases with lower intensity and short-to-moderate duration, then refuel ahead of the day's second session. Coaxing the body into burning fat more readily or fine-tuning the insulin response etc. rather than doing it when a 10 x 400 m session is scheduled.
I'm not sure I agree with these studies. Prior to intermittent fasting I was 230 lbs, 400 testosterone. After a year of IF I was 205lbs, 780 testosterone and increasing performance levels from speed and distance.
Further to this, cortisol is used to break down protein into glucose through gluconeogenesis, hence when your body isn’t fat adapted it resorts to muscle for protein and less so on your fat stores for energy. Very important and there is still no talk of this.
Very true. They don't even mention insulin and the havoc that plays with everything. So hey go and eat carbs, produce loads of insulin, inflammation and basically compromise too many physiological functions to mention here. This is a very subjective video.
@@StuClifton Very disappointing to say the least. Espeically when a race like comrades (which coach parry writes/helps people train for), is 90km and run in the mid aerobic heart rate zone which is majority fat burning. Why keep spiking insulin throughout a long run and throwing the body into more stress. Hence, high cortisol! Some coaches just aren't adaptable to new information and will live in the past, aka "Ancel Keys" Diet Heart Hypothesis. And that is exactly what it is, a hypothesis. No studies to definitively prove fat is bad for you. Funny that. Coach Parry isnt really a good source of information for diet these days.
There are assertions made here that are inconsistent with the conclusions of the first study. The study authors even stipulate that more research is needed. I don't run in a fasted state. I will run in the afternoons, after meals, or mornings, and my mornings usually have a cup of coffee with cream, but no solid food.. Muscle glycogen tends to be preserved on endurance runs, and indeed, if you've been training properly and are working mostly in Zone 2, fat will be the primary fuel source, so a fasted run in Zone 2 should not be a big obstacle. There might be some incidental glucose burn, but that is quickly and easily replenished with liver glycogen (liver holds about 80 grams of glucose, of 320 kcal). Sensationalist thumbnail is sensationalist. I expect better from this channel.
I can attest to everything that you have said about the female body, intermittent fasting, weight loss and gain, and running performance, over time. I lost the weight, I gained performance for a bit, then I felt exhausted all of the time and I gained weight no matter what I did. My endometriosis contributed especially since I was on hormones.
Exhaustion and weight gain will happen if you calorie-deficient. It got nothing to do with fasting. You can maintain calories while fasting; that will fix the problem.
Definitions are important here. The first article was about calorie deficit. The participants had an 18 hour eating period. So kind of not "intermittent fasting". It is important to define the difference between "Calorie restriction" and "intermittent fasting with adequate nutrition" as popularized by Dr. David Sinclair in the podcast for lifespan. Intermittent fasting is about When you eat, not necessarily about going into a calorie deficit overall.
Makes sense Shona. A body deprived of food shrinks by 2 sizes but puts on again by the next meal which has to be quite substantial to make up for the loss of calories. Energy can’t be stored in the body for long. One thing the body recognises n welcomes readily is food…. not exercise!!
Thank for all the consistant uploads and information. I feel im becoming a smarter runner because of this channel. This channel was one the first I learned a lot from when I started to becoming interested in running since C19. When content was just Brad and coach Parry 😅. What a great team 💪
Thanks Shona and Devlin for the interesting video. I know Michael Mosley is big on intermittent fasting, but I decided it was not for me a few years ago. I'm glad Devlin clarified at the very end of the video that these are just 2 studies, as more research is definitely needed to be more conclusive. As a social science PhD graduate and researcher, I feel a broader range of studies must be done before athletes can be confident they are following the right advice in these areas. I'm not sure if you have done one yet, but a video on the keto diet might be useful. That fad continually pops up in the social media groups I follow. Also, if there is any reliable research on the importance of magnesium in ones diet, that would be good as well. Regards, Patrick O'Leary
This is a limited and incomplete assessment of IF. You dont have to fast everyday. It is a tool for staying healthy. There are many ways to incorporate IF into your athletic or fitness program while appreciating the hormonal issues and differences between the sexes. Eg If you train at 6 am you can break your fast at 7 , fast another 10 to 12 hours, eating again. If your have 2 workouts , morning and evening, you can eat right after and fasting between. The health benefits can be good for performance as well. It is critical though that your meals provide good quality nutrition (ideally whole food plant based ) when you do eat. IF can be tailored to any training or workout program.
Hi Shona... May you please do a science study (if you haven't done it already) on getting a stitch during a run I suffered this during my comrades marathon two weeks ago Thank you
Thanks guys, good to get the science to the community! However it would be interesting to include effect of diet RE high fat or high carb. I see some good comments on this. Maybe you guys can find some research on this?
I found this video very useful! I have found that if I don't eat properly after a training session, I get moody. I do most of my training in the morning before I eat. I do think discussing science from different angles are always valuable. Also, I have to find what works best for me, because what I take out of all these studies are that even though there are many bodies that follow a certain path, there are enough that do not.
I've been a runner for 9 years and the last 2 1/2 years, I've been doing intermittent fasting for 16 hours. Running on a fasted state improved my performance considerably. My HM had come down from 1:45-1:35. 10k had also changed from 48-43. I do all my runs on a fasted state and the maximum distance I ran was 32km. I never had issues with recovery. During my peak training, I ran 6 days a week with a weekly mileage of 100+km.
Do you use any gels or other supplements during the run?
@@phipao none. Just water
Wow, this video is subjective. This is about 2 papers, and there are many more that would echo the same opinion. But what about all the scientific literature that supports fasted training. What about the benefits of being "fat adapted". Considering the majority of people are exercising and training (and a lot even racing) at a level at which using fat as an energy source is more stable, I find it very strange that such a subjective view is being presented. Right out of the Ancel Keys playbook.
Why are we hearing nothing about fat as a fuel. Which is what IF is about. Aerobic level exercise will burn mostly fat. IF is not just about reducing calorie input. It is about reducing insulin production to allow more fat burning.
Low insulin levels along with a well published finding that there is a significant increase in human growth Hormone! No mention of these positive factors and how the hgh production may prevent muscle wasting
Bullshit with muscle wasting.
I do a 10 hour eating window for IF 8a-6p and it gives my body time to fully digest before sleeping. It improves my sleep quality and keeps me from overeating. If I do run in the morning before eating, I’ll always keep it in zone 2 since I’m essentially glycogen depleted in that state. I do my hard runs in the afternoon a couple hours after breakfast and then have a healthy lunch and dinner to aid recovery. It’s been working
I did my first 15k fasted yesterday and I had no noticeable energy loss and it was actually my fastest time yet! I was however fasting before I started training running and have never had an affinity or need for food in the morning.
It’s very clear Coach Parry knows a lot about running, but very little about nutrition and metabolism. What she says about how the body reacts to IF is totally wrong. She stumbles through what she thinks and mentions insulin not once. Managing insulin levels by eating low carb and IF is key to good short and long term health.
If you listen to a video made in 2018, it is clear there has been no progression in understanding since then. The key really is insulin.
The video doesn't talk about the use of salt to increase the use of energy into the bloodstream. Also doesn't talk about are the subjects long term IF or newbies. Long term have taught the body to use fat reserves as an energy source.
No mention of sodium plus it will take at least a month to get used to not eating 3 meals a day, so that you metabolically switch to using your fat stores of which you have plenty. I have found since fasting that my running has improved lost the extra weight and feel more energetic.
IF, training in a fasted state, cutting out carbs, KETO diet; they improve you as a runner. Ever heard of Mark Sissen, Bruce Fordyce, Dr Phil Mafatone all very respected people who have achieved and follow fasting lifestyle. Shauna and crew know very little abt nutrition clearly.
We all naturally intermittently fast, it's called night time! Unless you're eating till midnight then eating again at 6am, you're doing a daily prolonged fast. Some foods can take many hours to fully digest, I think we're fine doing a morning run before breakfast! If you can't, it means you are probably pretty insulin resistant and you'd actually benefit from fasting longer.
So when my body is telling me it needs fuel, I should probably eat - got it, thanks! 😊
How do you know the cortisol etc will increase from day to day to day? The studies looked at a 24hr period. You cant determines what happens after a few weeks. Sorry
What about the massive 1800% rise in HGrowth Hormone associated with fasting? That is definitely affecting exercise beneficially.
Very interesting. Is there any indication of the exercise intensity ?
There are historical examples of intermittent fasting - Van Aaken's school being one, the Swedish / Ron Hill carbo-bleed-then-load being another - but they'd combine fasting/low carb phases with lower intensity and short-to-moderate duration, then refuel ahead of the day's second session. Coaxing the body into burning fat more readily or fine-tuning the insulin response etc. rather than doing it when a 10 x 400 m session is scheduled.
I just eat pizza. The end!
I'm not sure I agree with these studies. Prior to intermittent fasting I was 230 lbs, 400 testosterone. After a year of IF I was 205lbs, 780 testosterone and increasing performance levels from speed and distance.
This is true for high carb dieting endurance athletes. But high fat, different story. Mr Parry, please cover high fat diets already.
Further to this, cortisol is used to break down protein into glucose through gluconeogenesis, hence when your body isn’t fat adapted it resorts to muscle for protein and less so on your fat stores for energy. Very important and there is still no talk of this.
Very true. They don't even mention insulin and the havoc that plays with everything. So hey go and eat carbs, produce loads of insulin, inflammation and basically compromise too many physiological functions to mention here. This is a very subjective video.
@@StuClifton Very disappointing to say the least. Espeically when a race like comrades (which coach parry writes/helps people train for), is 90km and run in the mid aerobic heart rate zone which is majority fat burning. Why keep spiking insulin throughout a long run and throwing the body into more stress. Hence, high cortisol! Some coaches just aren't adaptable to new information and will live in the past, aka "Ancel Keys" Diet Heart Hypothesis. And that is exactly what it is, a hypothesis. No studies to definitively prove fat is bad for you. Funny that. Coach Parry isnt really a good source of information for diet these days.
How do I decrease weight? But now I train a lot but my weight goes down slow as I a going to run Comrades what I suppose to do?
There are assertions made here that are inconsistent with the conclusions of the first study. The study authors even stipulate that more research is needed. I don't run in a fasted state. I will run in the afternoons, after meals, or mornings, and my mornings usually have a cup of coffee with cream, but no solid food.. Muscle glycogen tends to be preserved on endurance runs, and indeed, if you've been training properly and are working mostly in Zone 2, fat will be the primary fuel source, so a fasted run in Zone 2 should not be a big obstacle. There might be some incidental glucose burn, but that is quickly and easily replenished with liver glycogen (liver holds about 80 grams of glucose, of 320 kcal). Sensationalist thumbnail is sensationalist. I expect better from this channel.
So what is coach parry definition of intermittent fasting?
i’m glad you’re still open minded in the conclusion, i have a feeling the low carb picture isn’t complete, long term adapting to ketones is important
I can attest to everything that you have said about the female body, intermittent fasting, weight loss and gain, and running performance, over time. I lost the weight, I gained performance for a bit, then I felt exhausted all of the time and I gained weight no matter what I did. My endometriosis contributed especially since I was on hormones.
Exhaustion and weight gain will happen if you calorie-deficient. It got nothing to do with fasting. You can maintain calories while fasting; that will fix the problem.
Wow i think theres alot of misleading information here
Definitions are important here. The first article was about calorie deficit. The participants had an 18 hour eating period. So kind of not "intermittent fasting". It is important to define the difference between "Calorie restriction" and "intermittent fasting with adequate nutrition" as popularized by Dr. David Sinclair in the podcast for lifespan. Intermittent fasting is about When you eat, not necessarily about going into a calorie deficit overall.
My reas9j for IF was mental clarity and better gut health and sleep which i have but i do worry about the other stufd
Makes sense Shona. A body deprived of food shrinks by 2 sizes but puts on again by the next meal which has to be quite substantial to make up for the loss of calories. Energy can’t be stored in the body for long. One thing the body recognises n welcomes readily is food…. not exercise!!
What do you think 45lbs of fat hanging on the belly of an obese for 10 years is if not energy stored for too long?
Thank for all the consistant uploads and information. I feel im becoming a smarter runner because of this channel. This channel was one the first I learned a lot from when I started to becoming interested in running since C19. When content was just Brad and coach Parry 😅. What a great team 💪
Thanks Shona and Devlin for the interesting video. I know Michael Mosley is big on intermittent fasting, but I decided it was not for me a few years ago. I'm glad Devlin clarified at the very end of the video that these are just 2 studies, as more research is definitely needed to be more conclusive. As a social science PhD graduate and researcher, I feel a broader range of studies must be done before athletes can be confident they are following the right advice in these areas. I'm not sure if you have done one yet, but a video on the keto diet might be useful. That fad continually pops up in the social media groups I follow. Also, if there is any reliable research on the importance of magnesium in ones diet, that would be good as well. Regards, Patrick O'Leary
that’s expected if they aren’t adapted to use ketones
This is a limited and incomplete assessment of IF. You dont have to fast everyday. It is a tool for staying healthy. There are many ways to incorporate IF into your athletic or fitness program while appreciating the hormonal issues and differences between the sexes. Eg If you train at 6 am you can break your fast at 7 , fast another 10 to 12 hours, eating again. If your have 2 workouts , morning and evening, you can eat right after and fasting between. The health benefits can be good for performance as well. It is critical though that your meals provide good quality nutrition (ideally whole food plant based ) when you do eat. IF can be tailored to any training or workout program.
Hi Shona... May you please do a science study (if you haven't done it already) on getting a stitch during a run
I suffered this during my comrades marathon two weeks ago
Thank you
Thanks guys, good to get the science to the community!
However it would be interesting to include effect of diet RE high fat or high carb. I see some good comments on this. Maybe you guys can find some research on this?
I found this video very useful!
I have found that if I don't eat properly after a training session, I get moody. I do most of my training in the morning before I eat.
I do think discussing science from different angles are always valuable. Also, I have to find what works best for me, because what I take out of all these studies are that even though there are many bodies that follow a certain path, there are enough that do not.
Sth africans and new zealanders. All so authoritative
The quality of this channel is superb.
Great video.