Lactate (lactic acid?) and What It Actually Does

This article will cover:

• Understanding energy and how it is created
• Acidity in muscle
• How lactate averts acidity
• How lactate is used to create energy
• Protocols and supplements to increase performance by reducing acidosis

 Lactic acid is a bit of a misnomer. When we are exercising lactate is the molecule that would accompany not lactic acid. Contrary to popular belief, lactate is not the culprit for the burn, reduced performance, or the subsequent soreness of muscles. Lactate is a metabolite used for fuel and preventing acidity in the muscle.

To understand the role of lactate lets first go over 5 important things: ATP, Hydrogen, Glycolysis, and Aerobic and Anaerobic metabolism.

For muscle to contract, energy is required. ATP hydrolysis occurs providing energy, but this also results in the release of hydrogen ions.

Increasing free hydrogen within muscle lowers pH (more acidic) and impairs the performance of the muscle. Hydrogen is to blame for the burn.

Glycolysis is the process of converting glucose into pyruvate. The splitting of 1 glucose into 2 pyruvate molecules generates some ATP.

Aerobic metabolism is the process of creating ATP in the presence of oxygen. After glycolysis, pyruvate goes into mitochondria and continues a process that generates 19 times more ATP than glycolysis alone. H₂O and an increased respiration of CO₂ to restore a balanced pH.

Anaerobic metabolism is the process of creating ATP in the absence of oxygen. ATP generation is solely from glycolysis. Because of the lack of oxygen, pyruvate bonds to hydrogen creating lactate. Lactate is pyruvate + hydrogen. The action of lactate binding to free hydrogen staves off acidity in the muscle, prolonging performance.

Now we understand lactate is a byproduct of anaerobic metabolism, and it binds to hydrogen to buffer acidity to allow for continued performance.

How is lactate also a fuel?

Lactate is an efficient and preferred fuel source because it has already undergone glycolysis. Since lactate is simply pyruvate + Hydrogen, and pyruvate is glucose broken down to be used as fuel that means lactate can be again used as fuel as soon as it can get rid of its hydrogen. This will happen once there is oxygen available. The oxygen will take and bind to the hydrogen becoming H₂O (water), and the resulting pyruvate can then go through aerobic metabolism to generate ATP.

In other words, in the absence of oxygen lactate prevents acidity and upon the availability of oxygen lactate will be used as an efficient fuel.

How can you apply this information?

Supplements

Sodium bicarbonate (baking soda) can be ingested 60 – 120 minutes before exercise to reduce acidosis and increase performance. Exogenous HC03 from sodium bicarb provides additional buffering capacity that appears to result in performance enhancing effects.

See the linked systematic review below for more in-depth information and analysis.