Lactic acid is a term we’ve all heard before, but knowing exactly what it is, how the body produces it, and its role in guiding training zones can sometimes be lesser known. This page will help explain what lactic acid is and how different training intensities can affect lactic acid production.
What is Lactic Acid #
Lactic acid is a molecule which is produced by our muscles when there is a lack of oxygen being delivered to tissues.
Lactic acid production happens under anaerobic conditions, and it is a quick method of generating energy under high intensity situations. The downside to lactic acid production is it causes a buildup of metabolites inside muscles and causes stiffness and perceived pain while exercising at high intensity.
When you are exercising in higher zones, there can be a substantial increase in lactic acid production and it is responsible for the stiff, burning feeling you experience in your muscles.
How is Lactic Acid Produced #
In the absence of oxygen, our muscles take glucose (sugar molecule) and convert it to lactic acid. Glucose metabolism is a complex series of chemical reactions which produce energy the body uses to move, and when there is a lack of oxygen glucose molecules do not go through the full chain of reactions.
By failing to go through all chemical reactions, each glucose molecule produces less energy than it otherwise would, and the end result is production of lactic acid molecules.
The harder you exercise, the higher your lactic acid production, and at very high intensities your body will produce very high levels of lactic acid very quickly which will result in high levels of fatigue resulting in exercise failure.
The Role of Lactic Acid in Training #
Many high performance athletes will measure lactic acid levels to help manage training intensity for a given session. Different cutoff values will be used to determine if an individual is in zones 1, 2, 3 or 4 and it can be very useful in directing training.
Measuring lactic acids levels are also useful in tracking changes in fitness over time. One of the goals of training full time is to push the boundaries of our training zones so it is possible to tolerate higher levels of training intensity at lower levels of lactic acid output. When this is accomplished, it is possible for people to achieve higher levels of performance which is an end goal of a training program.
As fitness improves, you’ll notice it’s possible to push yourself harder while producing same or lower levels of lactic acid, which then allows you to train at a higher level and push the boundaries of your fitness even more.
