Have you ever been really sore following an insane workout, and had someone tell you it was “Lactic Acid Build Up”? Well, I’m sorry to tell you this, but Lactic Acid has nothing to do with you being sore, unless we’re talking about during the workout– That could actually cause soreness fora minute or so. If you’re sore after a workout, it’s something called “DOMS:” “Delayed Onset Muscles Soreness.”
To start, what is Lactic Acid? Without getting too far into it: Lactic Acid is a by-product of Anaerobic Glycolysis.
The chemical breakdown of glucose for the production of “ATP” (Adenosine Triphosphate- Most easily described as a unit of energy for muscles) without oxygen (During weight lifting, sprinting, etc.) produces lactic acid; When oxygen is present (Jogging, running, bicycling, etc.), the process is “Aerobic,” and instead of producing Lactic Acid, your body produces Pyruvic Acid, which can then be used to fuel other oxidative processes for energy metabolism. There are two methods for removing Lactic Acid after production: Oxidation into Pyruvic Acid to fuel the Krebs Cycle, or it can be converted into Glucose in the liver via Gluconeogenesis for energy.
Science aside, what does that mean? Your body produces a chemical that can cause momentary “burn” in muscles because you’re exerting yourself, and then clears the pathways shortly thereafter. Think of it like this– Let’s say you have to climb 10 flights of stairs. For the first flight or two, you will “feel the burn” in your legs, because your body hasn’t increased respiration to increase oxygen supply, so your body is producing energy through Anaerobic Glycolysis. After the fourth flight of stairs, your body has increased respiration, and is now producing Pyruvic Acid instead of Lactic Acid, and you’ve begun an anaerobic workout– At the same time, the increase in oxygen supply is allowing some of the Lactic Acid to go through oxidation, while the rest is being shuttled to the liver.
Here’s another example to demonstrate that it can’t “build up:” You climb 2 flights of stairs– The entire process was Anaerobic, so your body produced Lactic Acid; You feel the burn in your legs as your arrive at your destination on the third floor. After a very short while, your legs no longer burn. Why? You’re now in an aerobic method of energy metabolism– You’re not taking in any more oxygen, but you’re also no longer exerting yourself; The Lactic Acid was converted to Pyruvic Acid for energy metabolism. (Anything left over was then sent to the liver.)
So, if someone says they’re suffering from Lactic Acid buildup from a few days ago. . . They’re not. What they’re experiencing is “DOMS.” DOMS is soreness, inflammation, and pain associated with particularly tough workouts, workouts too intense for the trainee, or a workout that involves intense movements the trainee is unaccustomed to. It’s often felt between 24 and 72 hours post workout, and is the result of microscopic tears in the muscle tissue that lead to inflammation and soreness.
DOMS is very unpleasant, but is not a sign that you did anything wrong, unless you’re just starting a workout plan– In that case, DOMS means that you started off too intensely and should have ramped up.