• All new members please introduce your self here and welcome to the board:
    http://www.professionalmuscle.com/forums/showthread.php?t=259
Buy Needles And Syringes With No Prescription
M4B Store Banner
intex
Riptropin Store banner
Generation X Bodybuilding Forum
Buy Needles And Syringes With No Prescription
Buy Needles And Syringes With No Prescription
Mysupps Store Banner
IP Gear Store Banner
PM-Ace-Labs
Ganabol Store Banner
Spend $100 and get bonus needles free at sterile syringes
Professional Muscle Store open now
sunrise2
PHARMAHGH1
kinglab
ganabol2
Professional Muscle Store open now
over 5000 supplements on sale at professional muscle store
boslabs1
granabolic1
napsgear-210x65
monster210x65
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
DeFiant
UGFREAK-banner-PM
STADAPM
yms-GIF-210x65-SB
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
wuhan2
dpharma
marathon
zzsttmy
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
azteca
crewguru
advertise1x
advertise1x
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store
over 5000 supplements on sale at professional muscle store

News about Lactic Acid

Coopie

Member
Registered
Joined
Oct 26, 2004
Messages
683
From Today's New York Times:

Lactic Acid Is Not Muscles' Foe, It's Fuel
By GINA KOLATA
Everyone who has even thought about exercising has heard the warnings about lactic acid. It builds up in your muscles. It is what makes your muscles burn. Its buildup is what makes your muscles tire and give out.

Coaches and personal trainers tell athletes and exercisers that they have to learn to work out at just below their "lactic threshold," that point of diminishing returns when lactic acid starts to accumulate. Some athletes even have blood tests to find their personal lactic thresholds.

But that, it turns out, is all wrong. Lactic acid is actually a fuel, not a caustic waste product. Muscles make it deliberately, producing it from glucose, and they burn it to obtain energy. The reason trained athletes can perform so hard and so long is because their intense training causes their muscles to adapt so they more readily and efficiently absorb lactic acid.

The notion that lactic acid was bad took hold more than a century ago, said George A. Brooks, a professor in the department of integrative biology at the University of California, Berkeley. It stuck because it seemed to make so much sense.

"It's one of the classic mistakes in the history of science," Dr. Brooks said.

Its origins lie in a study by a Nobel laureate, Otto Meyerhof, who in the early years of the 20th century cut a frog in half and put its bottom half in a jar. The frog's muscles had no circulation — no source of oxygen or energy.

Dr. Myerhoff gave the frog's leg electric shocks to make the muscles contract, but after a few twitches, the muscles stopped moving. Then, when Dr. Myerhoff examined the muscles, he discovered that they were bathed in lactic acid.

A theory was born. Lack of oxygen to muscles leads to lactic acid, leads to fatigue.

Athletes were told that they should spend most of their effort exercising aerobically, using glucose as a fuel. If they tried to spend too much time exercising harder, in the anaerobic zone, they were told, they would pay a price, that lactic acid would accumulate in the muscles, forcing them to stop.

Few scientists questioned this view, Dr. Brooks said. But, he said, he became interested in it in the 1960's, when he was running track at Queens College and his coach told him that his performance was limited by a buildup of lactic acid.

When he graduated and began working on a Ph.D. in exercise physiology, he decided to study the lactic acid hypothesis for his dissertation.

"I gave rats radioactive lactic acid, and I found that they burned it faster than anything else I could give them," Dr. Brooks said.

It looked as if lactic acid was there for a reason. It was a source of energy.

Dr. Brooks said he published the finding in the late 70's. Other researchers challenged him at meetings and in print.

"I had huge fights, I had terrible trouble getting my grants funded, I had my papers rejected," Dr. Brooks recalled. But he soldiered on, conducting more elaborate studies with rats and, years later, moving on to humans. Every time, with every study, his results were consistent with his radical idea.

Eventually, other researchers confirmed the work. And gradually, the thinking among exercise physiologists began to change.

"The evidence has continued to mount," said L. Bruce Gladden, a professor of health and human performance at Auburn University. "It became clear that it is not so simple as to say, Lactic acid is a bad thing and it causes fatigue."

As for the idea that lactic acid causes muscle soreness, Dr. Gladden said, that never made sense.

"Lactic acid will be gone from your muscles within an hour of exercise," he said. "You get sore one to three days later. The time frame is not consistent, and the mechanisms have not been found."

The understanding now is that muscle cells convert glucose or glycogen to lactic acid. The lactic acid is taken up and used as a fuel by mitochondria, the energy factories in muscle cells.

Mitochondria even have a special transporter protein to move the substance into them, Dr. Brooks found. Intense training makes a difference, he said, because it can make double the mitochondrial mass.

It is clear that the old lactic acid theory cannot explain what is happening to muscles, Dr. Brooks and others said.

Yet, Dr. Brooks said, even though coaches often believed in the myth of the lactic acid threshold, they ended up training athletes in the best way possible to increase their mitochondria. "Coaches have understood things the scientists didn't," he said.

Through trial and error, coaches learned that athletic performance improved when athletes worked on endurance, running longer and longer distances, for example.

That, it turns out, increased the mass of their muscle mitochondria, letting them burn more lactic acid and allowing the muscles to work harder and longer.

Just before a race, coaches often tell athletes to train very hard in brief spurts.

That extra stress increases the mitochondria mass even more, Dr. Brooks said, and is the reason for improved performance.

And the scientists?

They took much longer to figure it out.

"They said, 'You're anaerobic, you need more oxygen,' " Dr. Brooks said. "The scientists were stuck in 1920."
 
It's not new that lactic acid can be used as a fuel source or that Delayed-onset muscle soreness (DOMS) is not caused by lactic acid.

But I'm confused - are they saying LA is not responsible for causing the burning sensation following intense activity? If it is, how can LA not be "bad" or "caustic" as mentioned in the article?
 
Lactic acid is created from excess pyruvic acid which is created during glycolysis. Skeletal muscle continuously create lactic acid even while at rest, not just during anaerobic exercise. However, since lactic acid can be created without oxygen it is often referred to as an 'anaerobic metabolism'.

Lactic acid definitely is a fuel that is used in particular by the heart and slow-twitch muscle fibers, in fact lactic acid can move easily between the muscle cells and the bloodstream, and cells can either convert it back to pyruvic acid, which then enters the Krebs cycle to produce energy or it can be converted into glucose or glycogen which enters glycolysis to produce energy. Whereas other fuels need insulin to carry them across cell membranes, lactic acid uses a much faster carrier process called facilitated transport. The majority of lactic acid is removed via oxidation when used by your muscles as fuel, and the rest is converted back to glycogen.

As per its name, lactic acid is an organic acid, and as such an accumulation will increase the acidity levels within the muscles and hinder performance by causing muscle fatigue. This only occurs once you have exceeded you lactate threshold, which is when your energy demands are such that your body is converting so much glucose that it is creating also more lactate than what your muscles can oxidize. Although lactic acid can be created without oxygen, it does need oxygen in order to be converted into fuel for your muscle. So, in order to increase your lactate threshold, you need to increase the body's ability to deliver oxygen, and increase the facilitated transport process by increasing levels of the protein carrier MCT1 which allow the transport process to take place.
 
JasonWojo said:
It's not new that lactic acid can be used as a fuel source or that Delayed-onset muscle soreness (DOMS) is not caused by lactic acid.

But I'm confused - are they saying LA is not responsible for causing the burning sensation following intense activity? If it is, how can LA not be "bad" or "caustic" as mentioned in the article?

I think the article is an over-simplification. It is not bad or caustic when levels are such that it can all be utilized as fuel. When the intensity of exercise rises to a point that too much lactic acid is produced, this hinders athletic performance. So, lactic acid can be both good, and also bad in excess amounts.
 
Last edited:

Staff online

  • pesty4077
    Moderator/ Featured Member / Kilo Klub

Forum statistics

Total page views
575,826,266
Threads
138,424
Messages
2,856,934
Members
161,423
Latest member
Asap1124
NapsGear
HGH Power Store email banner
yourdailyvitamins
Prowrist straps store banner
yourrawmaterials
FLASHING-BOTTOM-BANNER-210x131
raws
Savage Labs Store email
Syntherol Site Enhancing Oil Synthol
aqpharma
yms-GIF-210x131-Banne-B
hulabs
ezgif-com-resize-2-1
MA Research Chem store banner
MA Supps Store Banner
volartek
Keytech banner
musclechem
Godbullraw-bottom-banner
Injection Instructions for beginners
YMS-210x131-V02
3
thc
YMS-210x131-V02
Back
Top