What Is Lactic Acid? How to Prevent Buildup

December 29, 2023

Lactic acid (or rather, lactate) is produced in response to demanding physical activities that stress the muscles and cause an increased need for energy. In this way, it’s a response that naturally makes you want to slow down and rest when your muscles are stressed and you’re exerting lots of energy.

The more often that someone trains, especially if that person repeatedly does the same types of intense exercises, the less he or she will feel the effects of lactic acid/lactate (like muscle soreness). In other words, highly trained athletes become adapted to short periods of high lactic acid levels, which means they have increased tolerance for its uncomfortable effects.

What can you do to perform more like a highly trained athlete? As explained more below, some of the ways you can prevent too much lactic acid — along with lactic acidosis — include gradually building up exercise intensity, staying hydrated, stretching, taking enough rest days, and fueling with good nutrition before and after workouts.

What Is Lactic Acid? Role in Body and Exercise

The definition of lactic acid is “an organic acid (C₃H₆O₃₎ present especially in muscle tissue as a by-product of anaerobic glycolysis, produced in carbohydrate matter usually by bacterial fermentation, and used especially in food and medicine and in industry.”

In other words, it’s a natural acid produced in the muscles and red blood cells, especially during strenuous exercise. That’s because lactate can be converted to energy without using oxygen.

In addition to being found in the human body, it’s also a colorless, syrupy acid formed in fermented/sour milk products, such as yogurt. Lactic acid fermentation helps create foods that contain healthy probiotic bacteria.

Lactate vs. lactic acid: What’s the difference?

When it comes to the effects these two have on the body, we often hear these terms used interchangeably. But according to experts the term “lactic acid” is actually an outdated construct and poorly understood.

Lactate is actually what is produced by your body in response to aerobic exercise, not lactic acid. The difference between the two comes down to their chemical compositions.

Lactate is lactic acid that is missing one proton. Lactic acid donates a proton and then becomes its conjugate base, lactate.

However, because many people still refer to the effects of lactic acid and not lactate, that’s how it’s mostly described in this article.

What does lactic acid do to the body?

Most people are under the impression that lactic acid in muscles causes soreness and stiffness.

However, according to a Scientific American article written by Stephen M. Roth, a professor in the department of kinesiology at the University of Maryland:

Contrary to popular opinion, lactate or, as it is often called, lactic acid buildup is not responsible for the muscle soreness felt in the days following strenuous exercise. Rather, the production of lactate and other metabolites during extreme exertion results in the burning sensation often felt in active muscles.

Because lactate/lactic acid buildup contributes to painful sensations during exercise, it prevents us from overworking and injuring ourselves. It causes us to slow down, essentially “forcing a recovery period in which the body clears the lactate and other metabolites.”

How Lactic Acid Is Produced

Lactic acid is produced in higher-than-normal amounts during tough aerobic exercise, since intense physical activity causes the muscles to need more oxygen. When exercise is vigorous enough to cause a high demand for oxygen that the lungs and heart can not keep up with, then lactic acid builds up in the blood.

Lactic acid levels increase in some of the following situations:

During strenuous exercise (this is the most common reason among healthy adults).
When someone experiences heart failure, liver failure or pulmonary embolism. For example, the liver normally breaks down lactic acid, but when it comes damaged or fails this process becomes impaired.
When a severe infection develops, such as sepsis.
When someone takes the medication called metformin (usually given to manage diabetes).
In response to severe dehydration and/or overheating.
Due to conditions that affect the blood, such as severe anemia or leukemia.
Due to carbon monoxide poisoning, alcohol poisoning or poisoning caused by consumption of chemicals like antifreeze (ethylene glycol).
Due to nutrient deficiencies, including low thiamine/B vitamins.

When your body’s oxygen level is low, such as during intense exercise, it breaks down carbohydrates for energy. This process produces lactic acid. Here’s a bit more about why and how this happens:

Working muscles generate energy anaerobically from glucose through a process called glycolysis.
Glycolysis takes place when glucose is broken down or metabolized into a substance called pyruvate. This takes place via the Embden-Meyerhof pathway.
The body temporarily converts pyruvate into lactate, which allows glucose breakdown and energy production to continue during short bursts of intense exercise.
This type of anaerobic energy production can power muscles for about one to three minutes.
Lactate levels rise during this time, causing muscles to become more acidic and fatigued, which typically puts a stop to such intensity.
Eventually lactate exits cells and is transported to the liver, where it is oxidized back to pyruvate and converted to glucose via the Cori cycle.

Is lactic acid harmful to the body?

What does it mean when your lactic acid is high? High lactic acid as a result of exercise is a normal reaction of the body, temporary and not harmful for the most part.

However, when lactic acid levels rise significantly, this is called lactic acidosis, which is considered to be life-threatening.

Lactic acidosis occurs when either the body makes too much lactate or when the body can’t clear lactate quickly enough. This can be due to many different factors, some of which include:

use of medications
very intense exercise
respiratory failure
heart disease
anemia
and others

Symptoms of lactic acidosis are above and beyond normal muscle fatigue. They can include:

trouble breathing/rapid breathing
excessive sweating
abdominal pain
nausea
vomiting
confusion
and sometimes coma

Can you die from lactic acidosis? It’s possible, although treatment helps control symptoms from escalating in many cases.

What is a normal lactic acid level?

Your doctor can perform a blood test in order to measure if your level falls within the normal lactic acid level range. Sometimes if an infection that affects the brain is suspected to have developed, then the amount of lactic acid in spinal fluid may be measured instead of taking a blood sample.

A normal range of lactic acid when measured in venous blood is between 0.5–2.2 milliequivalents per liter (mmol/L, or mEq/L). This is about equal to 4.5 to 19.8 milligrams per deciliter (mg/dL).

A normal range when measured in arterial blood is between 0.5–1.6 mmol/L. Arterial measurements are usually more accurate, but they are more difficult to perform than regular blood tests using blood from a vein.

Lactic acid in foods

In addition to the human body, you’ll also find lactic acid in some fermented foods. Lactic acid bacteria, for example, are found in cultured dairy products (or “sour milk” products) like yogurt and kefir.

This acid is formed via anaerobic respiration that is carried out by bacterial strains such as Lactobacillus and others.

Lactic acid fermentation, which helps produce probiotic foods, is a metabolic process in which glucose and other six-carbon sugars are converted into cellular energy and the metabolite lactate.

According to Science Direct, “Lactic acid fermentation is the most extended fermentation process and depending on the microbes employed, the milk obtained can be classified in thermophilic, probiotics, and mesophilic sour milks.”

How to Prevent Too Much Buildup

What is the fastest way to get rid of lactic acid? Recall that as mentioned above, lactic acid itself is not responsible for “delayed-onset muscle soreness” (or DOMS), which produces severe muscle tenderness after tough workouts.

Soreness, stiffness and loss of strength and range of motion usually peak about one to three days after the extreme exercise takes place, but how intense these symptoms are does not depend on how much lactic acid accumulates during exercise.

The exact reason that DOMS occurs is still being researched, but experts believe that an inflammatory-repair response taking place in your muscles is mostly to blame. Muscle cell damage and elevated release of various metabolites surrounding muscle cells seem to be involved.

You can still work on preventing lactic acid buildup in order to improve your workout capacity and recovery. Here are tips for keeping lactic acid levels in check:

1. Build Up Exercise Intensity Gradually

If you ramp up the intensity of your workouts too abruptly, you’ll pay for it by experiencing lots of muscle fatigue (among other symptoms within a couple days’ time).

Give yourself time to build stamina and strength gradually without putting yourself at risk for injury or burnout. You can also prevent overuse injuries by varying the types of workouts you do, the muscles you target and the intensity of exercises you perform.

Ideally split your weekly workouts into different types: those that are more aerobic in nature (cardio workouts) and those that build strength.

How do you know if you’re working at an appropriate intensity? You can monitor your breathing and heart rate.

Practice effective breathing techniques, and also consider using a pulse oximeter during exercise.

If you feel you’re overexerting yourself, slow down and avoid short, shallow breaths, and instead focus on slowing your breathing.

2. Fuel with Proper Nutrition

Be sure to fuel your muscles and organs with the nutrients your body needs, including adequate complex carbs, proteins and micronutrients from a variety of whole foods.

The best way to ensure you get enough calories and nutrients to support your fitness level is to eat a variety of foods, including protein sources, healthy fats, fruits, vegetables, high-fiber foods like nuts and seeds, etc.

Foods that provide electrolytes, especially magnesium and potassium, seem to be especially helpful for managing muscle fatigue during exercise. This means that eating natural sources of these minerals is a good idea for anyone who’s active — such as nuts, legumes, leafy greens, potatoes, bananas, broccoli, natural orange juice and dark cocoa.

Iron is another mineral that is helpful for fueling your body with oxygen. Iron-rich foods include:

liver and organ meats
grass-fed beef
lentils
leafy greens
fish
black beans
nuts

Prior to a workout, and afterward, it can be helpful to eat a source of carbs and protein that your muscles will use for energy. Examples include some fruit or oatmeal with yogurt or cottage cheese or a hard-boiled egg and slice of sprouted grain bread.

3. Take Rest Days

Your body only has a chance to clear out lactate and other metabolites that have built up from tough workouts once you take the time to rest. This is actually when your muscle tissue is repaired and you “grow back stronger.”

This means muscle recovery is an important piece of the fitness puzzle.

Even on rest days you can do light exercises, such as walking, gentle yoga or swimming. But don’t push yourself to exercise at a high intensity if you’re already feeling sore and tired; listen to your body and take at least one or more days off to rest per week.

4. Stretch and Gentle Movement

Stretching before and after a workout supports performance and recovery in several ways, such as by increasing blood flow, improving flexibility and also by mentally improving energy/focus.

Try dynamic stretches before exercise that involve moving your body (rather than holding deep stretches), which boosts circulation. Following exercise you can also use ice packs, get a massage and take warm baths to increase circulation and help manage soreness you may be feeling.

5. Prevent Dehydration

Make sure to drink enough water to prevent symptoms of dehydration and overheating, which can include fatigue, dizziness and cramps. Aim for at least eight glasses per day or more if you’re active or in a very hot climate.

Risks and Side Effects

While high lactic acid levels in response to physical exertion should not pose a risk for otherwise healthy people, lactic acidosis can increase the risk of serious complications and even death in people who are already ill.

Always immediately seek medical help if you develop signs of lactic acidosis. If you have an existing health condition that puts you at risk, discuss intense exercise with your doctor before starting a new program.

Final Thoughts

What is lactic acid? It’s an organic acid that builds in the body under certain circumstances, especially during strenuous exercise.
What does lactic acid do? It’s mostly produced in the muscles and red blood cells and leads to fatigue and soreness. It forms when the body breaks down carbohydrates to use for energy when oxygen levels are low.
Lactic acid in the body is produced by intense exercise, among other causes like infections, some diseases, certain medications and even poisoning.
Experts consider the lactic acid normal range to be between 0.5–2.2 milli-equivalents per liter (mmol/L, or mEq/L ) when a venous blood sample is used.
Wondering how to get rid of lactic acid? If exercise caused your levels to rise, they should drop down to normal levels with rest and time. Other ways to manage levels include staying hydrated, stretching, taking enough rest days and fueling with good nutrition.

What Is Lactic Acid? How to Prevent Buildup