by David C. LaPorte
Department of Biochemistry
University of Minnesota
Minneapolis, MN 55455
1. Lactic Acid: How/why is it formed?
The body has two ways to use glucose: aerobic and anaerobic glycolysis. Aerobic
glycolysis is more efficient because electrons which are liberated from glucose are
transferred to oxygen. This process produces energy which the cell can trap as ATP. When
there isn't enough oxygen, the cell needs some other way to dump these electrons or the
system will back up and stop. The cell dumps these electrons into pyruvic acid, a product
of glucose, converting it to lactic acid.
What is the necessary role it plays?
Lactic acid is a waste product which results from anaerobic glycolysis. However,
the liver can convert it back to glucose by gluconeogenesis.
BTW, the "lactic acid burn" that you get when you go anaerobic is not
the result of the high levels of lactate in your blood. Subjects who were given high
levels of sodium lactate did not suffer any of the symptoms to being anaerobic. These
symptoms result from the drop in pH of the blood which results from dumping acid into it.
You'd get the same symptoms from anything that produced acidosis.
Is there a way to recover from build up quickly both through diet and activity?
First, lactic acid clears from the blood and tissues (and pH recovers) very
quickly after exercise. Claims such as the need for massage to remove lactic acid hours
after a workout are simply wrong. (Massage can certainly be beneficial, but it isn't
needed to get rid of lactic acid.)
Second, the reason that lactic acid levels increase dramatically above the
so-called anaerobic threshold are uncertain. Two main theories are usually proposed:
Some folks think that lactic acid increases because, as the body no longer has
enough oxygen to meet all of its energy needs, lactic acid production goes up. (BTW, even
when you've gone anaerobic, you're still processing lots of oxygen. It simply isn't enough
to meet all your needs.) According to this theory, lactic acid levels simply reflect the
rate of production.
Another theory (which is getting a lot of support) focuses on the rate of lactate
consumption rather then production. Lactic acid which is generated in a working muscle is
being consumed in other tissues, such as the liver and other muscles. The level of lactic
acid in the blood is effected by both the rates of production and consumption. As the
working muscle works harder, it produces more lactic acid. This is balanced by the
abilities of the other tissues to consume more lactic acid. However, when the rate of
production of lactic acid is greater then the fastest rate at which other tissues can
consume it, blood lactic acid goes up dramatically.
To understand this better, think of a bucket with a hole in the bottom. You turn
on the garden hose and direct the stream into the bucket. The bucket starts to fill with
water, but water is leaking out the hole. As the water level goes up, the water leaks out
faster. When the leak is running as fast as the hose, the level stabilizes. Increase the
flow from the hose a little and the bucket will fill a little more until the leak is now
going as fast as the hose again. However, if you increase the flow from the hose too much,
the rate of the leak will not be able to match it. The bucket will fill up and overflow.
The flow from the hose is like the production of lactic acid from the working
muscle, the level of water in the bucket is like the blood lactic acid level and the leak
is like the tissues which are using lactate. When the rate of production of lactate
exceeds the rate at which it can be consumed, the blood lactic acid shoots up and you go
As far as what you can do about it, there are some folks who think that general
fitness and regular anaerobic exercise can improve the abilities of your nonworking
muscles to consume lactic acid.
Sodium bicarbonate buffering has been suggested for people to neutralize lactate
(lactic acid) buildup during high intensity weight training. The MAJOR problem is that
since it is sodium bicarbonate, taking it will jack up your sodium levels incredibly. One
teaspoon is something like twice the daily maximum and effective buffering requires a good
bit more. We considered the idea of using Calcium Carbonate, but apparently bicarbonate is
effective at a different pH range and CaCO3 would not have the same benefits. And
remember, high sodium levels contribute directly to high blood pressure, which is not a
good thing when training hard.
"Muscle Memory": A Theoretical Concept Based on
Muscle Structure and Function
ECA (Ephedrine, caffeine and aspirin) stack