Question about lactic acid

HEYYO

I don't know much on the topic, but here's a silly question.

Does lactic acid make you tired. For example, if one were to put lactic acid in a needle, injected into their muscles while starting off exercising, let's say, would that injection tire you out? I know you'd be pretty stupid to do that, but for the sake of principle is it the acid that knocks you out early?

JAPANic

It would tire you out in that your body would have to deal with getting it out of the system.

The muscle fatigue or tiredness would only result from over use of the muscle and a lack of oxygen.

I imagine it would be a lot like drinking your own urine.
Only more painful and harder for your body to deal with.

I'm only guessing though....

Is it the lactic acid that causes muscle pain or is the pain just caused by over use and repair? Or a mixture of the both?

Don't try this at home kids...

Duckwah

injecting lactic acid into yourself would be a very fast way to get fatigued and i can imagine it would be very painful at the injection site.

Secondly lactic acid is responsible for the burning/heavy feeling during intense exercise but is not reponsible for DOMS (delayed onset muscle soreness) which is aches and pain the day after a hard session

thats caused by microtrauma to the muscles and the bodies subsequent efforts to repair the muscle

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dhk

Slightly off-topic, but can anyone tell me why it's called lactic acid, or lactate? Does the fluid look milky, or is it related in some way to lactation? Dumb question, I know.

Dan

dhk

OK, found my answer on-line. It is the same acid that's in sour milk, cheese and yogurt, and is also produced in the anerobic fermentation of cabbage (eg sauerkraut). Apparently the process is closely related to the anerobic glycolysis which occurs in the muscles.

Dan

HEYYO

Very interesting dhk. As I am lactose intollerant, would this effect anything?

Ted B

No. Being lactose intolerant simply means that your body does not produce lactase, which is the enzyme required to metabolize lactose (natural dairy sugar).

JuneBug

LA gets turned into other stuffs that your body likes while you are working out . your liver is turning it into glycogen. yeah. energy stuffs. So dont get all hated at it. LA is just what it is. it is not a bad thing it just got a bad rap.

how well you clear it out...well. .. that is all due to two factors. 1) genetics. and 2) training. .. !
You can read about all this in any physiology book.

one good training book is 'training for cyclists' by dave phinney? and carpenter?
its at amazon. its a GREAT book to read while doing a recovery ride. lots of gems.

2LAP

Lactic acid and Lactate - same substance and most of the time can be used in place of each other.

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JuneBug

Sorry it is not glycogen but its part of the gluconeogenesis process that is done in teh liver. it gets turned into glucose. By the time you are done with your workout it is pretty much cleared out. Training teaches the body to clear it out quicker and more efficiently. start your workouts with some good sprints to 'wake it up' and then proceed.
something like that.

JuneBug

YOu know what?
I changed my mind.
Booooo Lactic Acid. Boooooo.
It becomes GLUCOSE?? I can eat a SKittle for that! SKittles....nice. goood glucose....nice....
Lactic acid. ....hurt. ! Baaad Lactic acid BAD.

OK I just had to get that off my chest.

JuneBug

YOu know what?
I changed my mind.
Booooo Lactic Acid. Boooooo.
It becomes GLUCOSE?? I can eat a SKittle for that! SKittles....nice. goood glucose....nice....
Lactic acid. ....hurt. ! Baaad Lactic acid BAD.

OK I just had to get that off my chest.

Dinesh

btw Lactose is a SUGAR found in Milk
Like GLUCOSE etc.

Lactic acid is a result of anerobic respiriation i.e. in the absence of o2.

aussie71

Hi
Lactic acid is the by-product of anaerobic metabolism. It is analagous to ethyl alcohol production formed during fermentation in yeast etc... mmmbeer.... Normally under conditions with adequate O2 (aerobic exercise) however, glucose travels thru the glycolytic pathway to form pyruvate (half a glucose molecule). Along the way NADH is converted to NAD+. Without NADH this glycolysis will cease. And so at the end of glycolysis is a process called the electron transport system that assimilates O2 to generate CO2 + H2O (C comes from glucose) and replenish the supply of NADH and also generate ATP. Sounds complicated but pictures work wonders.
Where does lactic acid come from???
When under reduced O2 tension (anaerobic) the cells cannot go to this final step of the electron transport system and require another pathway.
And so Pyruvate is then converted to lactate and cycled back to the liver in the "Cori cycle". This alternative process is where lactate comes from and serves to replenish the energy carriers during glycolysis under ano2 conditions. Moreover it is not the actual lactic acid which produces fatigue. It is the consequent drop in pH that renders glycolytic enzymes less functional.