Myfitnesspal

Message Boards Fitness and Exercise
You are currently viewing the message boards in:

Lets talk glycogen stores - in non-athletes/women

yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
I'm trying to find some information on the size of glycogen stores in normal people, and here especially in women. I know that the liver can store a substantial amount of glycogen, and the muscles have a lower concentration, but of course the amount of muscles is higher than the 'amount' of liver.

With this I want to know how much of that is accessible and how long normal women (smaller, less muscles) can run without bonking, given they are fit enough to keep up. Also, I wonder if this is time or distance limited as most papers talk about time until bonking and not distance. But of course everyone runs at a different pace, and especially non-athletes won't be that fast.
«13

Replies

  • sijomialsijomial Member, Premium Posts: 17,932 Member Member, Premium Posts: 17,932 Member
    Other factors to consider:

    A highly trained / bigger volume exerciser will be able to store more glycogen as a result of their training compared to a low volume exerciser.

    Intensity and speed is a personal comparison but not a comparison between different people of different abilities. As a moderate ability cyclist my maximum intensity for an hour is double many unfit people but half of an elite rider - that's one hell of a range.

    Your ratio of glycogen to fat used during your exercise has a wide range due to intensity. From my results when my RER was tested a HR of 130bpm was my crossover point where glycogen started to overtake fat as the predominant fuel.
    Using the rough rule of thumb of 400g of glycogen / 1600cals for an average sized person I've seen quoted would suggest I could burn 3,200 cals before bonking at a gentle pace (130bpm) pace. Roughly five and a half hours but see below.

    But I don't tend to cycle that gently. At my more normal brisk pace I'm probably using x1.5 the amount of carbs per hour.

    As for the accessibility question my understanding is that muscle stores can only be used by the muscles and can't be returned from muscle storage for general (including brain) energy use. Perhaps @heybales can confirm?
    That would change the calculations above as then glycogen stored in my upper body muscle mass wouldn't be much use when cycling.

    Not sure if gender is a dirrect factor or if it's just that women would TEND to be lighter, TEND to carry less muscle mass as a general rule. But general rules are for cohorts not individuals.


    edited February 18
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    Thanks a lot Sijomial, those are some really good considerations. I'd hoped you would show up, but .. cough.. as ever I could not figure out how to write your name properly. :# So glycogen stones in the legs would likely mostly power the legs when for example running? That's interesting and something I'd not considered. Would make sense, and would certainly reduce the available energy amount quite substantially.

    Hmm.. I wonder if I could get a RER test to see how I predominantly burn fuel as I feel there's something very, very off for me. But it's so difficult to say because I don't know what's normal. What's the name of such a test? I'm in fitness limbo here, but maybe something is available.

    edit: Oh, I might just have had such a test, in a medical setting. Will need to ask the doc for the raw data. Maybe there's something interesting in it. So far I only have the results of a blood gas test (ever had someone poke holes into your wrist when you're approaching max intensity? It's interesting to say the least. :D )
    edited February 18
  • cmriversidecmriverside Member Posts: 30,881 Member Member Posts: 30,881 Member
    Didn't you do a thread recently about your inability to process energy properly?

    I don't remember the reasons but it is a significant pathology, isn't it? Seems relevant here.
  • FitAgainBy55FitAgainBy55 Member Posts: 88 Member Member Posts: 88 Member
    Is this a question born of curiosity or are you trying to use this for race preparation ?
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    Didn't you do a thread recently about your inability to process energy properly?

    I don't remember the reasons but it is a significant pathology, isn't it? Seems relevant here.

    Yes, but I'm trying to understand what is normal, and not what's possibly going on with me. That's a difference.
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    Wow, thanks a lot Heybales!Super interesting, and actually I had to laugh about calves hitting the wall while the rest of the body didn't. This is so much stuff I didn't know. And never thought about. I really need to give this a proper reading and thinking over the weekend. *mind blown away*
    edited February 18
  • sijomialsijomial Member, Premium Posts: 17,932 Member Member, Premium Posts: 17,932 Member
    Glad I tagged Heybales!
    Wealth of good knowledge.

    My RER results were from a sports science lab as part fo the procedure for a VO2 max and max HR test - in my case a stationary bike ramp test to failure using the ASCM protocol.
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    Thanks a lot Sijomial,
    I might do this one day just because it's interesting. Apparently the doc who did the exercise testing has the data, but is not willing to share (it's my data!). Oh well... But just because I'm curious it might be worth doing, and it's not even that expensive - outside of Covid that is. At the moment such testing centers are only allowed to provide medical services, and as such they only offer sport medical examinations with exercise test. Meh!
  • ninerbuffninerbuff Member, Greeter, Premium Posts: 44,288 Member Member, Greeter, Premium Posts: 44,288 Member
    yirara wrote: »
    Thanks a lot Sijomial,
    I might do this one day just because it's interesting. Apparently the doc who did the exercise testing has the data, but is not willing to share (it's my data!). Oh well... But just because I'm curious it might be worth doing, and it's not even that expensive - outside of Covid that is. At the moment such testing centers are only allowed to provide medical services, and as such they only offer sport medical examinations with exercise test. Meh!
    Have you ever experimented at all doing long bouts then recarbing on the go (like with gel packs) and seeing how you perform?


    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition

    9285851.png
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    sijomial wrote: »
    Glad I tagged Heybales!
    Wealth of good knowledge.

    My RER results were from a sports science lab as part fo the procedure for a VO2 max and max HR test - in my case a stationary bike ramp test to failure using the ASCM protocol.

    Ok, I do have some data from this exercise testing, but it's all over the place and partially wrong. Oh well...
    Can you help me understand this? (yes, I know this goes offtopic)

    Max power: 160 Watt, 149 % predicted
    VO2max: 28.6 ml/min /kg, 114 % predicted
    RER 1.13
    anaerobic threshold: 80W
    max HR: 191 /min , 110 % of predicted
    Breathing reserve 23 %


    The test was interrupted at 160 Watt. I could have gone on if I wasn't asked the whole time to take a deep inhale, take my hand off the bar for a blood test or do lots of other things which disrupted my cycling and especially breathing. My guess is that I wasn't even scratching a HR of 175 during this test, while I estimate my HRmax at 209 based on many years of running data. I can certainly still run at 191. Well, at the moment as I've not run in a while and my HR just shoots up a lot more. My 'i can still talk' and running with a 3/3 breathing rhythm hr is just below 178, which I guess to be at roughly 85% HRmax

    How I interpret this data: RER above 1 just means pure carbs I guess, probably measured at highest performance? Though no idea how you can get above 1 if you're looking at the ratio between two end members. VO2max... looks kind of ok when compared to running cooper tests, which I know are not all out for reasons (I get sick when I run all out). The anaerobic threshold seems very low, as in 80W is comfortable, brisk cycling I would say. So that's really the interesting thing for me here. But I guess they didn't actually somehow measure it but calculated it using 50% of maximum effort (which wasn't my max effort)

    edit: KITTEN! That's one messed up test! I just threw my data into a road bike calculator and found that 80 watts on my race bike corresponds to about 22kmh, and even less on my everyday bike. That's comfortable city cycling for me and probably for most people around here.
    edited February 18
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    ninerbuff wrote: »
    yirara wrote: »
    Thanks a lot Sijomial,
    I might do this one day just because it's interesting. Apparently the doc who did the exercise testing has the data, but is not willing to share (it's my data!). Oh well... But just because I'm curious it might be worth doing, and it's not even that expensive - outside of Covid that is. At the moment such testing centers are only allowed to provide medical services, and as such they only offer sport medical examinations with exercise test. Meh!
    Have you ever experimented at all doing long bouts then recarbing on the go (like with gel packs) and seeing how you perform?


    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition

    9285851.png

    Yes, a few years ago I trained for a half-marathon. I decided the best strategy for me would be to run 5km, followed by some walking and refueling. I got to 18km a week before the big day. And then got sick and remained sick for the coming weeks, but that's a different story totally which is totally not the aim of this thread. I'm merely interested in the workings of glycogen storage.
  • sijomialsijomial Member, Premium Posts: 17,932 Member Member, Premium Posts: 17,932 Member
    I'll try and find my test results tomorrow but your results at face value seem seriously weird!
    Was this with a mask on the whole time connected to a gas analyser or some other method?

    RER of over one was one of the indicators of maximal effort, but you don't seem to have been even close to maximal effort.
    80W anaerobic threshold for someone exercising regularly must be very unusual and perhaps indicative of your condition?

  • heybalesheybales Member, Premium Posts: 18,532 Member Member, Premium Posts: 18,532 Member
    yirara wrote: »
    sijomial wrote: »
    Glad I tagged Heybales!
    Wealth of good knowledge.

    My RER results were from a sports science lab as part fo the procedure for a VO2 max and max HR test - in my case a stationary bike ramp test to failure using the ASCM protocol.

    Ok, I do have some data from this exercise testing, but it's all over the place and partially wrong. Oh well...
    Can you help me understand this? (yes, I know this goes offtopic)

    Max power: 160 Watt, 149 % predicted
    VO2max: 28.6 ml/min /kg, 114 % predicted
    RER 1.13
    anaerobic threshold: 80W
    max HR: 191 /min , 110 % of predicted
    Breathing reserve 23 %


    The test was interrupted at 160 Watt. I could have gone on if I wasn't asked the whole time to take a deep inhale, take my hand off the bar for a blood test or do lots of other things which disrupted my cycling and especially breathing. My guess is that I wasn't even scratching a HR of 175 during this test, while I estimate my HRmax at 209 based on many years of running data. I can certainly still run at 191. Well, at the moment as I've not run in a while and my HR just shoots up a lot more. My 'i can still talk' and running with a 3/3 breathing rhythm hr is just below 178, which I guess to be at roughly 85% HRmax

    How I interpret this data: RER above 1 just means pure carbs I guess, probably measured at highest performance? Though no idea how you can get above 1 if you're looking at the ratio between two end members. VO2max... looks kind of ok when compared to running cooper tests, which I know are not all out for reasons (I get sick when I run all out). The anaerobic threshold seems very low, as in 80W is comfortable, brisk cycling I would say. So that's really the interesting thing for me here. But I guess they didn't actually somehow measure it but calculated it using 50% of maximum effort (which wasn't my max effort)

    edit: KITTEN! That's one messed up test! I just threw my data into a road bike calculator and found that 80 watts on my race bike corresponds to about 22kmh, and even less on my everyday bike. That's comfortable city cycling for me and probably for most people around here.

    That is the problem when at the upper reaches of effort - slight change to patterns can start you on downturn to appearing to reach max effort too soon.

    You did reach maxHR of 191 though, that's the test result. Even if not at HRmax yet.
    VO2max probably could have gone higher as you said weren't really done yet, but maybe they weren't seeing any more increase to it, it does tap out and you can keep HR going higher.
    AT would have been nice to show with HR too, not just watts.

    Their predictions are based on stat's, so not really useful except to see you did much better!

    Using some form of estimate, either the blood tests or curve formula - you hit AT at 80 watts, and kept going up to 160 W - that's pretty good range of anaerobic.
    Except most have AT around 85-90% of HRmax, which you are saying 191 wasn't even true HRmax.
    In your other topic, wasn't the description about inability was it to clear lactic acid at normal rate?
    I'm guessing your AT would be less than 85% then.
    Depends on what method was used to get the AT/LT figure, and then tie it to the data point for Watts at that moment. Hopefully you don't see Concini in the footnotes anywhere.

    https://www.sciencedirect.com/science/article/pii/S1728869X13000026


    Breathing reserve - just shows lungs have plenty to go - they aren't the chokepoint usually. Did you do a few inhales/exhales full force pre or post test?

    RER just means indeed showing a max of glycogen burn.
    It's ratio of CO2 produced to O2 taken in - so producing more CO2 than O2 taken in - past 1 it's not about energy source anymore.

    Just like you can get a RER reading after eating a meal, and that will skew higher but not because of current energy source, but digesting/processing food.
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    heybales wrote: »

    That is the problem when at the upper reaches of effort - slight change to patterns can start you on downturn to appearing to reach max effort too soon.

    You did reach maxHR of 191 though, that's the test result. Even if not at HRmax yet.

    Oh, you mean the maximum HR I reached on this test, and not my HRmax. Hmm.. good one. It seems very high to be honest. I ran in the evening and went up to 187 in the end (have not run in 2 months), and that was more strenuous. Can't look at Fitbit data here as they asked me to remove it near the end - another disturbance in the force! ehm.. my cycling.
    VO2max probably could have gone higher as you said weren't really done yet, but maybe they weren't seeing any more increase to it, it does tap out and you can keep HR going higher.
    AT would have been nice to show with HR too, not just watts.

    I'll try to get the actual data. They are supposed to give it to me if I ask for in, and not just a report with the end numbers. But this might go via a data access request. Yeah, I'd hoped to see AT with HR

    Using some form of estimate, either the blood tests or curve formula - you hit AT at 80 watts, and kept going up to 160 W - that's pretty good range of anaerobic.
    Except most have AT around 85-90% of HRmax, which you are saying 191 wasn't even true HRmax.
    In your other topic, wasn't the description about inability was it to clear lactic acid at normal rate?
    I'm guessing your AT would be less than 85% then.
    Depends on what method was used to get the AT/LT figure, and then tie it to the data point for Watts at that moment. Hopefully you don't see Concini in the footnotes anywhere.

    https://www.sciencedirect.com/science/article/pii/S1728869X13000026

    This is the confusing part. I found some sources online saying AT is calculated at 50-60% of max effort in people and at 75% in athletes. Which sounds odd, but would fit with the strange max 160 watt and AT 80 watt. But no, it makes no sense to me. I'm rather certain I'm not running anaerobically when cycling to the supermarket. Well, I hope anyway!
    Breathing reserve - just shows lungs have plenty to go - they aren't the chokepoint usually. Did you do a few inhales/exhales full force pre or post test?

    Yep. My body can be totally wasted after a slow jog, but my breathing is relaxed and I feel good in that respect. My cooper tests also feel like there's no problem in that respect.
    RER just means indeed showing a max of glycogen burn.
    It's ratio of CO2 produced to O2 taken in - so producing more CO2 than O2 taken in - past 1 it's not about energy source anymore.

    Just like you can get a RER reading after eating a meal, and that will skew higher but not because of current energy source, but digesting/processing food.

    Ah ok! I think I get it now. A number larger than 1 is attributed to among others bicarb buffering. Would be interesting to know at what HR or wattage the 1 was surpassed.

    Hmm.. so I guess I need to get my hands at the raw data somehow. I'm sure there's more interesting stuff in there. And especially need to get it before I talk to my doctor again. This lung specialist just phoned a day earlier than I had an appointment, I had no access to this data above yet, and he just said "all is fine, I'm healthy and extremely fit for my age".

    ... which I feel has not really been taken into account. This test wasn't too difficult for me as it was short, but less strenuous than a constant high load which is one of my problems. It also wasn't long enough on lower load to get me anywhere near the other area I get problems at. Thus question is how representative it is.
  • mariomicromariomicro Member Posts: 86 Member Member Posts: 86 Member
    @yirara to add to what other posters have said, there's another factor to take in consideration. If you're fat-adapted (and if you are even only a semi-pro athlete, you will be, regardless of whether your diet is ketogenic or not), once your glycogen stores have run out, your body will start converting non glucose (eg protein) reserves into glycogen [1] and/or utilizing ketones from fat stores [2].

    [1] https://www.ncbi.nlm.nih.gov/books/NBK22591/
    [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1373635/

    Gluconeogenesis and ketogenesis can happen at the same time, because they are demand driven, not supply driven.

    Also check all the studies by Volek:
    https://pubmed.ncbi.nlm.nih.gov/?term=Volek JS[Author]&cauthor=true&cauthor_uid=31217353
    edited February 19
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    mariomicro wrote: »
    @yirara to add to what other posters have said, there's another factor to take in consideration. If you're fat-adapted (and if you are even only a semi-pro athlete, you will be, regardless of whether your diet is ketogenic or not), once your glycogen stores have run out, your body will start converting non glucose (eg protein) reserves into glycogen [1] and/or utilizing ketones from fat stores [2].

    [1] https://www.ncbi.nlm.nih.gov/books/NBK22591/
    [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1373635/

    Gluconeogenesis and ketogenesis can happen at the same time, because they are demand driven, not supply driven.

    Also check all the studies by Volek:
    https://pubmed.ncbi.nlm.nih.gov/?term=Volek JS[Author]&cauthor=true&cauthor_uid=31217353

    Ok, this is going far too offtopic now, but I'm not fat adapted. A few year ago I would hit the wall so hard after 65 minutes that I'd sit on the ground, completely confused for half an hour or so, then call a taxi to get home. If I remembered where I was. Now I at least managed to run for about 65 minutes but I manage to just get on for another 20 minutes. But once I stop running my whole body goes into a cramp that lasts 10 minutes or more, then limp home the last few meters, and then I feel rubbish for the next two days. I also only manage to hike, visit a museum, sit behind computer and work or cycle for a total maximum of 2 hours on good day. And believe me: I try to extend this every single time I go out and do something slow.
  • mariomicromariomicro Member Posts: 86 Member Member Posts: 86 Member
    @yirara I just wanted to add: search Dr. Benjamin Bikman's videos on Youtube. He's done a lot of research on the insulin to glucagon ratio, which, indirectly, deals with glycogen stores and will do a better job than I do at explaining the topic. Don't be put off by the fact he's often a guest of pro-keto channels, because what he deals with is of more general interest.
    edited February 19
  • yirarayirara Member, Premium Posts: 5,891 Member Member, Premium Posts: 5,891 Member
    mariomicro wrote: »
    @yirara I just wanted to add: search Dr. Benjamin Bikman's videos on Youtube. He's done a lot of research on the insulin to glucagon ratio, which, indirectly, deals with glycogen stores and will do a better job than I do at explaining the topic. Don't be put off by the fact he's often a guest of pro-keto channels, because what he deals with is of more general interest.

    Thanks a lot, I'll have a look. I assume it's not a Doctor Fung kind of person but an actual scientist? :D

    On that note: I have data! Lots of data! (meh, all in an image table!) Will be difficult to pull something useful out, but I go digging tonight. And I still have a couple of papers to read on glycogen stores.
    edited February 19
  • mariomicromariomicro Member Posts: 86 Member Member Posts: 86 Member
    yirara wrote: »

    Thanks a lot, I'll have a look. I assume it's not a Doctor Fung kind of person but an actual scientist? :D

    They are both in the medical profession and cite their sources. But there will be always be an amount of cherry picking when citing sources. I link a study that glorifies keto or fasting in mice. You cite an article that trashes keto or fasting in monkeys, and so on. You have to pick what is good for you and works for you and then make up your mind.
    edited February 19
Sign In or Register to comment.