Lactic Acid Build Up: What It Means and How to Get Rid of It

Lactic acid is created when the body turns glucose into energy. The production of lactic acid occurs when oxygen levels are low, generally during high-intensity exercise. Lactic acid build-up can hinder your exercise routine, so it’s important to understand why it happens and how to prevent it. 

What Lactic Acid Is

Lactic acid is produced in muscle cells and red blood cells. It forms when the body breaks down carbohydrates for glucose during exercise in certain conditions. “Lactic acid is a result of glycolysis (or the breakdown of glucose), an energy system that creates ATP energy in the absence of oxygen in muscle cells,” says Jenna Braddock, MSH, RD, CSSD, ACSM-CPT, owner of MakeHealthyEasy.com and OffSeasonAthlete.com. 

Braddock also notes that there is a difference between lactic acid and lactate. Although the two words are used interchangeably, they are not technically the same.

“This distinction helps us understand what is happening in the body; lactate is a fuel source for the body and has many important functions,” adds Braddock. During exercise, the working muscle cells can continue anaerobic energy production for one to three minutes, during which you can perform at high levels. 

Why Lactic Acid Builds Up

During high-intensity exercise, muscles require more oxygen than the body can take in, causing anaerobic respiration and lactic acid build-up. When lactic acid develops depends on a person’s fitness level. The body clears lactic acid when it develops, but it may not be able to keep up when the levels start to increase rapidly.

“This is often termed "lactate threshold" for high-intensity aerobic activities (like running), but keep in mind lactate accumulation can also occur with strength training,” says Chrissy Carroll, RRCA Running Coach at Snacking in Sneakers.

When this increased acid builds, the muscles get tired and may not be able to contract as effectively. Some people may notice a burning sensation in the muscle during exercise.

“Interestingly, some experts believe the production of lactate actually helps the muscles delay fatigue during intense exercise,” says Carroll. She also notes that contrary to popular belief, the lactic acid buildup is not what's responsible for delayed onset muscle soreness that occurs in the 24-48 hours after a workout.

How to Get Rid of It

“Decreasing the exercise intensity, resting from the activity, and taking deep breaths may all be helpful ways to clear lactic acid during an exercise session,” says Carroll.

Another proven method for clearing lactic acid is engaging in active recovery after exercise. Low-intensity movements, like yoga, walking, biking, or foam rolling, may clear lactic acid from the body.

A study compared active and passive recovery in 14 downhill skiers and found that active recovery caused a greater decrease in lactic acid. Skiers who performed the active recovery were able to move faster and complete more runs. 

How to Prevent Lactic Acid Build-Up

“The feeling of burning and fatigue that is associated with lactic acid can be improved most significantly through training,” says Braddock. She recommends increasing volume, intensity, and duration of training gradually to prevent lactic acid buildup.

But, “you do not have to avoid lactic acid build-up completely,” according to Carroll. “It's normal for certain training regimens to include high-intensity intervals that are completed above the lactate threshold, couched between easier training days and/or rest days, to allow for proper training adaptations and recovery,” Carroll adds.

Braddock also notes that fueling properly for a workout can positively affect lactic acid levels. “Beta-alanine is a supplement that can be used to delay the impacts of lactate accumulation, but it may negatively impact other areas of performance,” says Braddock.

She also urges athletes to work with an experienced sports dietitian to develop a fueling and supplement plan that’s right for them. 

A Word From Verywell

Lactic acid buildup is not necessarily a bad thing. It’s a natural byproduct within the body that supports anaerobic activity and helps individuals train at high levels. However, too much lactic acid can lead to performance deficits and burning within the muscle. Increase your training volume, intensity, and duration over time to prevent lactic acid buildup in the future.