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Fast twitch muscle fibres and mitochondrial function?

Jenny TipsforME

Senior Member
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1,184
Location
Bristol
A slightly random thought about mitochondrial stuff:

In my 23andme info it talks about me potentially being a sprinter. My first reaction was obviously :rofl: yes right! But this is to do with fast twitch fibres in how the muscle is made up proportionally. So I have proportionately more fast twitch fibres

"which are lighter in coloring than slow-twitch fibers due to the low levels of myoglobin (the iron-containing protein found in muscle cells that stores oxygen for use in cell respiration) and mitochondria they possess...
The fast-twitch fibers, however, were re-classified due to observed differences in their properties. Fast-twitch fibers now have two subcategories: Fast-Glycolytic (FG) or Fast-Oxidative-Glycolytic (FOG), or 2b and 2a fibers respectively. FG fibers differ from FOG fibers in their pure fast-twitch properties.

They have few mitochondria and high levels of stored glycogen and the enzymes necessary for producing energy without oxygen. The FOG fibers have the stored glycogen and enzymatic properties of FG fibers, in addition to high levels of oxidative enzymes which assist aerobic metabolism. They have the best of both worlds."
https://www.bodybuilding.com/fun/drobson33.htm (I don't know which type I have more of)

This seems like it might go more wrong, if you also have a tendency to mitochondrial disease or dysfunction?! Eg The hallmark of slow twitch fibres is fatigue resistance, so I'm just speculating that having fewer than average of these may not be serving me well in my current circumstances.

IMG_2656.jpg


Has anyone looked into this? Eg @JaimeS or @Valentijn have you thought about this?
 

Jenny TipsforME

Senior Member
Messages
1,184
Location
Bristol
This is interesting, I missed it at the time.

"
Int J Immunopathol Pharmacol. 2009 Apr-Jun;22(2):427-36.
Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study.
Pietrangelo T1, Toniolo L, Paoli A, Fulle S, Puglielli C, Fanò G, Reggiani C.
Author information

Abstract
Chronic fatigue syndrome (CFS) is a disabling condition characterized by unexplained chronic fatigue that impairs normal activities. Although immunological and psychological aspects are present, symptoms related to skeletal muscles, such as muscle soreness, fatigability and increased lactate accumulation, are prominent in CFS patients. In this case-control study, the phenotype of the same biopsy samples was analyzed by determining i) fibre-type proportion using myosin isoforms as fibre type molecular marker and gel electrophoresis as a tool to separate and quantify myosin isoforms, and ii) contractile properties of manually dissected, chemically made permeable and calcium-activated single muscle fibres. The results showed that fibre-type proportion was significantly altered in CSF samples, which showed a shift from the slow- to the fast-twitch phenotype. Cross sectional area, force, maximum shortening velocity and calcium sensitivity were not significantly changed in single muscle fibres from CSF samples. Thus, the contractile properties of muscle fibres were preserved but their proportion was changed, with an increase in the more fatigue-prone, energetically expensive fast fibre type. Taken together, these results support the view that muscle tissue is directly involved in the pathogenesis of CSF and it might contribute to the early onset of fatigue typical of the skeletal muscles of CFS patients."

I don't think we can tell from this study whether CFS participants had genetic leaning towards fast twitch or if the onset of CFS caused it.
 

pattismith

Senior Member
Messages
3,926
I am in the Elite athlete group too!:rofl:
(30 % of europeans are homozygous for the fast twitch allele, so it is not rare!)

Certainly a factor that could increase the risk for more severe muscles symptoms whenever mitochondrions cannot do their job properly for whatever reason.:thumbsup:

This is interesting, I missed it at the time.

"
Int J Immunopathol Pharmacol. 2009 Apr-Jun;22(2):427-36.
Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study.
Pietrangelo T1, Toniolo L, Paoli A, Fulle S, Puglielli C, Fanò G, Reggiani C.
Author information

I don't think we can tell from this study whether CFS participants had genetic leaning towards fast twitch or if the onset of CFS caused it.

it would be interesting to know if CFS patients have significantly more fast fibers than control, and are more carriers for the c allele than the general population!
 

pattismith

Senior Member
Messages
3,926
But I have rs1815739 CC too. I looked it up when I got my 23and me results because it seemed completely unbelievable.

:lol: is it?
When I was young, I had good predipositions for sprint and jump, and very poor dispositions to endurance
 

Richard7

Senior Member
Messages
772
Location
Australia
yeah @pattismith, I could argue that I was built for walking.

Though I now think that I have probably had problems with PoTS since I was 12 or maybe a bit earlier. I can remember issues with lightheadedness when getting up suddenly and problems with some of till then usual manouvers used in climbing trees at 11 or 12.
 

Jenny TipsforME

Senior Member
Messages
1,184
Location
Bristol
it would be interesting to know if CFS patients have significantly more fast fibers than control, and are more carriers for the c allele than the general population!

The results showed that fibre-type proportion was significantly altered in CSF [presume CFS typo as no CSF involved ;)] samples, which showed a shift from the slow- to the fast-twitch phenotype
So I think that's saying yes significantly more fast twitch fibres than controls. But didn't look into genetics of it.
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
Fast twitch fiber research goes back a long way. I think long before the 2009 paper, I vaguely recall reading about it in the 90s. It might even be from the 80s. I would be very interested in not only knowing the genotype, snps etc., but actual fiber measurements. Fast twitch fibers might be developed as a compensatory mechanism for ME. Or not. Its an interesting line of questioning.

If we adapt to ME then I would expect to see deconditioning of slow fibers, and more development of fast fibers. If we fail to adapt I would expect to see no such change. If fast twitch fiber proportion is a risk factor, it might be because slow fibers are not adequate to deal with the initial insult, and so lead to a path of slow fiber deconditioning, and fast fiber enhancement.

This is all speculation of course until the science shows otherwise.
 

PatJ

Forum Support Assistant
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5,288
Location
Canada
23andme figures I'm in the fast twitch group as well. This matches my past physical abilities - very quick at sudden motion such as sprinting, standing long jump, etc. but poor endurance.
 

Jenny TipsforME

Senior Member
Messages
1,184
Location
Bristol
Fast twitch fibers might be developed as a compensatory mechanism for ME

This is an interesting idea.

I wonder if it could fit in with any of the dauer/hypometabolism type stuff?

I did a quick google and found something opposite

"We find that animals in torpor exhibit a shift to slow-twitch Type I muscle fibers. This switch is accompanied by activation of the PGC-1α-mediated endurance exercise pathway. In addition, we observe increased antioxidant capacity without evidence of oxidative stress, a marked decline in apoptotic susceptibility, and enhanced mitochondrial abundance and metabolism." paper about hibernating squirrels

But in bears there's a small shift to proportionally more fast twitch in biceps, so a bit inconclusive about which way this might go.

I tried looking up Cell Danger Response and fast twitch fibres but didn't get anywhere with that.

If fast twitch fiber proportion is a risk factor, it might be because slow fibers are not adequate to deal with the initial insult,

If it's about the initial insult then it may not matter to us now, but if not might be worth upping slow twitch fibres. Is this possible?

"Can You Become a Slow-Twitcher?
With the 2004 Olympics still fresh on our minds, many will ask: Who has the right stuff to go the distance? Athletes like Olympic champion Frank Shorter are clearly exceptional and represent an extreme in human skeletal muscle phenotype. Realistically, few of us can ever hope to run a marathon in world-class time. However, there may be cause for some optimism for the average mortal, since endurance exercise training in healthy humans leads to fiber-type specific increases in the abundance of PGC-1 and PPAR-α protein in skeletal muscle (Russell et al. 2003).
Russell et al. 2003). Moreover, functional genomics support the concept that skeletal muscle remodeling to a ST phenotype, either through activated calcineurin or PPARδ, can protect against the development of dietary-induced insulin resistance (Ryder et al. 2003) and obesity (Wang et al. 2004). The results of these studies have clinical relevance since insulin-resistant elderly subjects and offspring of patients with type 2 diabetes mellitus have skeletal muscle mitochondrial dysfunction (Petersen et al. 2003; Petersen et al. 2004). Clearly, further translational studies in humans are required to test the hypothesis that increasing the proportion of ST oxidative muscle fibers will overcome the mitochondrial dysfunction and metabolic defects associated with insulin-resistant states." Skeletal Muscle Fiber Type: Influence on Contractile and Metabolic Properties.

Endurance exercise is off the table.

There's a study about Quercetin
"Quercetin for 7 days resulted in an increase in PGC-1 α and SIRT1 mRNA in slow-twitch [ slow fibers; see introduction ] muscles and in the brain (P <0.05). We found an approximately 100% increase in PGC-1α gene expression in the joint muscle for both doses and a 50% increase in brain after administration of 12.5 and 25 mg / kg. SIRT1 expression increased almost 200% in the muscle for both doses and by 50 and 100% in the brain... PGC-1 α expression is elevated in high-capacity mitochondrial systems ; It promotes the formation of slow-twitch muscle fibers and is a critical regulator of skeletal muscle fuel supplies, all of which are essential for endurance effort capacity" Found on https://mecvswetenschap.wordpress.com/tag/atp

Quercetin is easily available as a supplement (I think I might even have some) or in the skins of fruit etc. Of course we don't know if fewer slow twitch might be adaptive so we can't be confident that supplements are a good thing.

calcineurin is to do with T cells but my brain is out of juice for the day I think.

 
Last edited:

bertiedog

Senior Member
Messages
1,736
Location
South East England, UK
My 23andme results show I have fast twitch muscles too and I was an excellent sprinter when aged 11/12 and held a record for 100 yards sprint that was never beaten at my school (1959), I think it stood for around 15 years until the distance was changed to metres.

However I couldn't run the 400 yards as it was then, I would feel like I was dying and could never understand this at the time. I was probably 13 or 14 and always thought it was to do with my age!

Pam
 

Chrisb

Senior Member
Messages
1,051
I think long before the 2009 paper, I vaguely recall reading about it in the 90s. It might even be from the 80s.

I would confirm that this idea was being discussed in the 1980s. I had a muscle biopsy taken, probably between 1988 and 1990, and these matters were under consideration at the time.