What causes muscle fatigue?

[TINKRD]

Scientifically, what causes muscles to lose their strength over x amount of time/reps.

I know that the burning sensation is from lactic acid releasing, correct?

[jdgregory84]

I think that's pretty much what it is. Your brain releasing chemicals to make your muscles ache before there is catastrophic failure, or damage to the muscle occurs.

[davbrucas]

I think that's pretty much what it is. Your brain releasing chemicals to make your muscles ache before there is catastrophic failure, or damage to the muscle occurs.

Not quite.

There a couple ways that we experience muscle fatigue...central vs peripheral. In central fatigue your brain decreases action potential generation which reduces muscle contractability in an attempt by the CNS to prevent muscle injury. This fatigue usually comes before fatigue at the local level...this is why when you think you cannot do any more, you can usually be coersed to do a few more reps.
At the local level fatigue can happen by a number of methods. Muscles usually use oxidative phosphorylation and aerobic metabolism to generate energy. When work demand on the muscle is higher than it can output, the anerobic threshhold is reached and the muscle converts to anaerobic metabolism...the byproducts of this is lactic acid production. This is one of the ways muscles can fatigue at the peripheral level. Another is a mechanical decrease in the cross-linking of actin and myosin due to stress, decrease in calcium, etc.
Regular aerobic exercise will increase your anaerobic threshhold and allow more sustained exercise before fatigue.

This isnt a complete explanation of the biochemistry of muscle physiology, but I am about to load up the boat and go catch some redfish.
Hope this helped.

[stinginstang]

Not quite.



This isnt a complete explanation of the biochemistry of muscle physiology, but I am about to load up the boat and go catch some redfish.
Hope this helped.

since you put it in layman's terms..

[TINKRD]

Not quite.

There a couple ways that we experience muscle fatigue...central vs peripheral. In central fatigue your brain decreases action potential generation which reduces muscle contractability in an attempt by the CNS to prevent muscle injury. This fatigue usually comes before fatigue at the local level...this is why when you think you cannot do any more, you can usually be coersed to do a few more reps.
At the local level fatigue can happen by a number of methods. Muscles usually use oxidative phosphorylation and aerobic metabolism to generate energy. When work demand on the muscle is higher than it can output, the anerobic threshhold is reached and the muscle converts to anaerobic metabolism...the byproducts of this is lactic acid production. This is one of the ways muscles can fatigue at the peripheral level. Another is a mechanical decrease in the cross-linking of actin and myosin due to stress, decrease in calcium, etc.
Regular aerobic exercise will increase your anaerobic threshhold and allow more sustained exercise before fatigue.

This isnt a complete explanation of the biochemistry of muscle physiology, but I am about to load up the boat and go catch some redfish.
Hope this helped.

jesus, i'll need to re-read this about 5x, but thanks! lol

[davbrucas]

Sorry...was trying to give you a scientific answer.

[stangin4lyfe]

Sorry...was trying to give you a scientific answer.

Can you relay that in retard's terms please sir?



I've always been told that calcium leaks are the main suspect...

[ceyko]

Can you relay that in retard's terms please sir?



I've always been told that calcium leaks are the main suspect...

I often deal in terms I don't understand. You'll get it better if you google any word/phrase/acronym you don't understand and research it.

Problem is, sometimes you don't agree with a statement after you understand it better. Then you ask more questions and have to google more.

When I was learning some technologies it would take me 8 hours to understand a config because it can become a vicious cycle.

[stangin4lyfe]

I often deal in terms I don't understand. You'll get it better if you google any word/phrase/acronym you don't understand and research it.

Problem is, sometimes you don't agree with a statement after you understand it better. Then you ask more questions and have to google more.

When I was learning some technologies it would take me 8 hours to understand a config because it can become a vicious cycle.

LOL...I obviously don't have near the spare time that you do, so can you get right on that for me please sir?

[ceyko]

LOL...I obviously don't have near the spare time that you do, so can you get right on that for me please sir?

Well, when I want to know something I have to. I don't care that much, so it's all you.

[Flashstang04]

Utililzation of a set amount of adenosine triphosphate. (ATP). Creatine recycles this so it allows you 'a few more reps'. When you run out, contractile potential is lower and lower.

[jdgregory84]

Can you relay that in retard's terms please sir?



I've always been told that calcium leaks are the main suspect...

He just went more specific with what I said. You release chemicals saying "I'm not used to this...please stop." Go past that a little bit and you'll see an increase in.......whatever you're trying to increase. But there is a point where your body shuts down.