Lactic Acid, Facts and Fiction.

[MuscleScience]

Lactic acid seems to be one of the most misunderstood topics involved with exercise. I will attempt to separate fact from fiction.


Fiction: Lactic acid builds up in the muscles and other tissues

Fact: Lactic acid is toxic to cellular processes it is shuttled out of muscle cells almost as soon as it is produced. Once it hits the blood it is buffered by the blood because of the bicarbonate buffers in the blood. This compound is then called lactate.

Fiction: Lactic acid causes muscle soreness

Fact: Lactic acid causes the burn you feel in your muscles when you overwhelm the transport mechanisms in the muscle cell. One of the protective mechanisms is to cause pain when the pH of the muscle cell changes. This causes you to exercise less allowing the muscles to catch up.

Fiction: Lactic acid is a dead end metabolic byproduct

Fact: Lactic acid after it hits the blood is then called lactate (See Above). The lactate is then shuttled to the liver where it is processed by the liver back to pyruvate. With further processing it can be used to produce more ATP.

Fiction: Lactic acid can be reduced by stretching, deep massage, or the sauna

Fact: Lactic acid does not cause your muscles to be sore. It does not linger in the muscles. Soreness is caused by micro trauma to the myofibrils of the muscles after a workout.

Fiction: Lactic acid can cause your blood to become to acidic

Fact: This is partially true. In normal healthy individuals lactic acid will not change the pH of your blood. The blood has a built in buffering compound that strictly regulates the bloods pH. If if varies even by the slightest amount serious problems can occur. There Is a condition called Lactic Acidosis, this is most commonly seen in individuals that suffer from diabetes, liver or kidney disease. Can this be induced my exercise in a healthy individual, the answer to that is highly unlikely. Ask Lance Armstrong if you don't believe me.



These are all that I can think of right off the top of my head. If there are more please ask.

[moush]

good info bro! i like reading your posts very informative

[helium3]

fact: lactic acid combined with oxygen is also used as energy until you reach the threshhold, and the muscle then has to get rid of it.

youll know when youve crossed the lactic threshhold!

[MuscleScience]

fact: lactic acid combined with oxygen is also used as energy until you reach the threshhold, and the muscle then has to get rid of it.

youll know when youve crossed the lactic threshhold!

If you have a enough O2 you will not produce lactic acid in great amounts. I don't follow what your saying here.

[helium3]

If you have a enough O2 you will not produce lactic acid in great amounts. I don't follow what your saying here.

many people believe that lactic acid is only a biproduct produced in your muscles durin exercise, but fail to realise that is also used as energy.the more you exercise the more your body can "handle" the lactic acid, as your body becomes more efficient at shuttling lactic acid from the muscle the higher your threshhold becomes.

[MuscleScience]

many people believe that lactic acid is only a biproduct produced in your muscles durin exercise, but fail to realise that is also used as energy.the more you exercise the more your body can "handle" the lactic acid, as your body becomes more efficient at shuttling lactic acid from the muscle the higher your threshhold becomes.

Very true with training your muscle, liver, kidney and heart cells start to increasingly express an enzyme called lactate dehydrogenase. Which converts lactate back to pyruvate. Pyruvate is then used to generate glucose via the cori cycle but it is not an energy producing process it is an energy consuming process. Lactate can be used to produce energy when it is processed back to pyruvate only if there is sufficient amounts of 02 present to continue into aerobic pathways. So no energy is directly made from lactate.

Lactate threshold is just a definition to express how under intense energy demanding situations the levels of blood lactate are increasing at a higher rate than it is being processed.

[M302_Imola]

Man this is like BioChem deja vu! The Kreb cycle and all its pathways. Did someone just have a lesson covering this material?

[MuscleScience]

Man this is like BioChem deja vu! The Kreb cycle and all its pathways. Did someone just have a lesson covering this material?

No, I thought I would post up a general thread about it because I have seen a lot of threads lately that had the basic questions or misconceptions about the bold statements above.