Can our bodies forget how to use certain energy sources or possibly never have learned it?

yirara

Normally the body uses various sources for energy. In everyday life mostly a mix of fatty acids and glycogen, and to a lesser extend amino acids, and more obscure things like lactic acid if available, right?

For the past 30 years or more, since being a teenager I've been having crashes and since earliest childhood problems with strength/endurance/simple things like walking up inclines or running/lifting weights/etc/basically any kind of exercise. I kind of have the feeling that my body is mostly running on gycogen because the amount of energy is so limited and then I hit the wall. I've been running for 6 years now, but still don't get further than 10km without bonking. When I'm active in any way (also working behind a computer) then I can fast a max of 2 hours. Every attempt at trying to stretch this, or to be less dependent on (mostly slow) carbs ends in a massive crash that leaves me feeling miserable for several days. Every attempt at trying to be active before breakfast ends in a crash. Sometimes, just having a dinner with 7g more protein and 7g less carbs results in a crash. Don't ask how I felt over Christmas, trying to enjoy pork tenderloin for three days. The annoying thing is that I'm not the only one in my family with this issue. I never really thought it was an issue until my sis asked me to help with understanding something for her. And now I got sucked into this.

So basically, is there a way to teach your body to provide a steady flow of energy without being sick the whole time? I've been on a few trips lasting 2-3 weeks where carbs were more limited than I'm used to, and I felt weak, confused and miserable the whole time. Btw, my blood sugar is fine, and this is not a weight loss questions.

heybales

People can have messed up mitochondria and not be able to deal with processing glycogen fast enough for the needs required.

I've heard of similar regarding fat. It is possible - malfunctioning is malfunctioning.

Because that's what you are implying - it's doing fine on glycogen, can't use fat.

But if that's the case - 90% of daily life is fat burn, except brain, in the body. So I'd expect you to run out of glycogen stores well before you started running or doing cardio.

Interestingly, there is commonly enough glycogen stores in liver (if topped off) to supply the brain for 24 hrs if not topped off more, if the body isn't doing any activity to use more of them.
Then that is where you get into more ketones made when glycogen goes down, and brain can use that, along with a lot of other cells.

Is blood sugar readings still fine in tests after the normally required fasting period?

If so that would imply you must be burning fat just fine other times.

Just be clear on cardio bonking too - there are 2 points in time and many will call the 1st one bonking.
There is the point where blood sugar gets low, you feel tired due to that.
But the muscles have been using their own supply of stored glycogen since 5-10 min from the start.
That 1st point is mental from the low blood sugar the brain is facing. Usually there is enough liver stores to get past that and keep going.
Bonking or hitting the wall is the 2nd point - where the muscle stores have run out, and now rely on only fat as energy source.
They were getting a % of fat as source the whole time (unless sprinting all out), and can continue to use only fat.
At a much slower rate. Hence the massive slow down to whatever that rate is.
For some crawling, some walking.
Not all the muscles use up their stores at the same time either of glycogen, so some can barely keep going, some could be empty. It's why you get some of the interesting finishes in races.

But muscle glucose stores can't be put back into the blood stream for use elsewhere.

So without thinking of a specific medical issue - people have trained in such a manner that does NOT help the mitochondria use fat better or increase, which is the only way to make the glycogen last longer.
When very unfit that can happen, when training is nothing but full on intensity training only the glycogen usage is trained. Muscles can't ramp up to use more fat.

That sort of sounds like your case.

But you could also have messed up mito that can't ramp up or build more to use more fat - so you keep using glycogen at a rate like an unfit person.
Or you have lack of red blood cells and not getting enough oxygen around to use the fat better.

Several places where I know there can be a breakdown - and blood test would point out a couple of them.
Training methods would suggest a couple others.
And some muscle biopsy would be needed for other potentials if those don't point out an issue.

yirara

Hey Heybales,
I was kind of hoping that you would comment I'm super confused at the moment, thus please excuse my confusing post.

What you're writing, with brains working as long as I don't crash: Yes, well.. kind of. Could be a lot better at times. Blood sugar looking good: as well. So it doesn't make any sense to me either.
So I've been running for 6 years and still can't get further than 10km. The longer I go on the more my legs hurt and get heavy (running is never easy for me, mind!), the more I have the feeling that I'm at high altitude with low air pressure despite me running slower and slower, and then there's the point where too little air, burning legs and a complete lack of energy come together and I end up shivering, confused, all my muscles cramped up, weak, etc... I mostly do slow runs simply because I can't run faster. I know tempo runs have their place, but after 6 years of trying and using structured training plans I still don't get past 12 minutes max on good days. So my tempo run days are barely faster than 10ks or are over after a few minutes. Which again points towards a problem with glycogen. Argh! It all doesn't make sense! And inclines, any incline feels like my fast running attempts: lower legs just hurt badly and I can't lift them up anymore, someone stole all the oxygen and I need a microbreak every 50-300 steps, upon which I immediately feel fine again and can walk on for a few steps. Heart and lungs are totally healthy, btw. Give me lots of food and I walk a whole day, or cycle 100km. Take my food away and I crash after 2 hours max regardless of whether I work, stroll through a museum or go shopping. Yes, I've been trying for years to go without food for longer, but it just doesn't seem to work.

Guess it's time to find a doc for this, right?

heybales

A treadmill test with blood draw will be cheaper than biopsy, maybe, not sure how difficult that is now or expensive.

That test can show red blood levels after a bit of tired running, show up if lactic acid is way high (you could either produce well more than normal due to body thinking you are at high exertion levels, or have a problem clearing what should be average levels of lactic acid - your description of burning legs makes me think lactic acid involved), show up if blood sugar way low, see if electrolyte levels way off, ect.

It really doesn't sound like problem with glycogen - sounds more like a problem using fat more as source when it should be possible, and body instead is forced to rely more on glycogen, wiping out those stores.

Though lack of oxygen distro almost sounds like it's in there too - that also causes fat to not be used, more glycogen, and if anaerobic, more lactic acid produced.

Seen cases where red blood count in blood test is fine - but they aren't usable at level they should be for carrying oxygen.

Yep - I'd skip GP and right to specialist if it saves time/money and allowed.

And if you have recent blood test - don't allow them to waste time starting with that unless they are getting something special done.

yirara

Thanks a lot Heybales. I'll go to my gp and ask for a referral to a specialist. I think it's really time to get to the bottom of this. Here, I can only go via my gp, but generally all testing should be free. Unless it's not available here, which might be a possibility because insurances think it's too expensive . But that's something. To be honest, I always thought I just need to do better, but I'm slowly starting to realize that there's just might not be any better.

What you say about red blood cell levels kind of rings true. I've never been properly anemic because I always make sure it doesn't happen. But I start to feel like being at high altitude just walking along the seashore when ferritin drops below 30. Try to explain that to a doctor who thinks you should not have any problems until levels drop below 15. Suddenly this starts to make sense!

Ok, off to bed. My head is spinning. Still need to get some sleep. I'll probably get a GP appointment tomorrow as it's not really a problem here. Phew!

yirara

I just like updates: Went to GP today. She looked at me like and referred me to an internal specialist. I asked for endo, but apparently there's more gatekeeping for vague things that go on forever. Thus first internal medicine. Waiting times are currently 2 weeks. Thus not too bad.

claireychn074

Have you ever had your catecholamine levels a checked? If you get referred on further to an endocrinologist it might be worth asking for a test....

yirara

claireychn074 wrote: »

Have you ever had your catecholamine levels a checked? If you get referred on further to an endocrinologist it might be worth asking for a test....

I never had anything checked! I went to a cardiologist at around 20 when physically working out didn't work, and he just told me: "Hun, you're normal weight, your heart and lungs are fine. You just have to do better" Well.. 26 years later I apparently have not done my best in all those years. There's a difference between being theoretically fit enough to run a marathon and actually running one if running feels like you're running at an altitude of 4000m. (don't ask me how I actually feel like at high altitude).

And with regards to nothing done: nope, the acid-base problem I sometimes get after exercise has never been investigated either. Just a standard blood test, no follow up with an arterial blood gas test, thus I still don't know what's going on 6.5 years after this happened the first time.

claireychn074

@yirara Happy to give you some info about my own experiences if you want to message me. Everyone’s different but if it only excludes something for you, then that’s got to be a help in the long run!

ninerbuff

Since everything in the body is a chemical reaction, any disruption of regular processes will have different outcomes. Just like when people attain insulin resistance from disrupting their normal weight by getting very overweight or obese.

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

yirara

Oh great. So that's some answer: apparently I get lactic acidosis from actually very little exercise. So that's now certain. Sigh.

heybales

Hmmm - did they look at the red blood cells and their ability to carry expected levels of oxygen?

I'm still wondering why the body is producing that much in the first place, that would be like upper reaches of intensity in a workout to produce big quantities that can't be handled by the cells using it for energy, or liver processing it.

Explains a lot though. I guess when people talk about exercise and "feeling the burn" - you can remark you feel that often and easy.

One of those sorry they found something, but glad they found something.
Is there a next step?

yirara

Thanks a lot heybales. Yes, red blood cells are fine. Actually, even when I'm slightly anemic according to ferritin my red blood cells are middle of range, or even a bit higher. It seems like my body is producing them like crazy to transport as much oxygen as possible. Which again seems useless. I'll be discussing the results next week, and then we see what to do.