Lactate: What It Is, What Its Effects Are on the Body

Javier Colomer 10 min. of reading Sports Leave a comment

Today we’re going to check out what Lactate is (sometimes confused with Lactic Acid), why it’s produced, and how it can affect your performance.

If you want to squeeze the most out of your workouts, you gotta know, at least partly, how your body works. The best way to control it and neutralize its downsides is by understanding how it’s generated and metabolized.

What is Lactate?

This substance is produced by muscles during intense exercise

However, it’s been thought to be exclusive to this kind of activity, assuming lactate was just a metabolic waste product resulting from anaerobic effort (oxygen debt), or even blamed for post-exercise muscle soreness.

Lactate is produced due to a lack of oxygen during muscle contraction. Also, it’s established that lactate can be generated under aerobic conditions, with its production being the result of glucose use by muscle cells under certain aerobic conditions.

Lactate turns out not to be a metabolic waste product, but the most important gluconeogenic precursor (glucose synthesis) in the body

So, the higher the glucose demand by the cell, the greater the lactate production, independent of oxygen presence

Lactate buildup in muscles doesn’t make them tire faster; it can even help muscles contract more efficiently, which can boost endurance, just like the common belief used to be

Is Lactic Acid the Same as Lactate?

Even though they can be confusing, they’re actually not the same thing.

To get the difference, you gotta look at the chemistry: an acid is a substance that can donate hydrogen ions (H+). Lactic acid is one of those substances.

When it donates a hydrogen ion, the resulting product is called the acid’s conjugate base, which in this case is lactate

So, lactate is the ionized form of lactic acid, a metabolite

Symptoms of Lactate

The effect caused by lactate buildup is kinda unpleasant, no denying it…

This happens when too much acid accumulates in the bloodstream. If you’ve felt these sensations, it’s very likely you’ve experienced lactic acidosis, and of course, it’ll stick in your memory…

It’s your body’s way of telling you to stop what you’re doing. But this symptom is temporary

Muscle pain, burning, cramps, an increasingly intense feeling of exhaustion, rapid breathing, nausea, stomach pain, and in extreme cases, the urge to vomit…

Someone did the CrossFit Fran WOD, which might be the fastest way to experience what lactate can do to you…

How is Lactate Produced and How Does It Affect the Body?

The muscle contraction demand during high-intensity exercise recruits fast fibers (type II) for energy production. These fibers are highly glycolytic, so they generate a high amount of lactate at the cellular level.

During high-intensity activity, lactate production is much higher than at rest or during other activities, and there’s also the release of hydrogen ions (H+), leading to decreased muscle contractile capacity and altered blood pH.

This results in reduced contractile response and fiber power, meaning worse performance

The buildup of these molecules, not only from lactate but as part of the ATP energy process, can interfere with certain physiological processes, like competing with calcium: H+ can inhibit calcium release and its reabsorption by the sarcoplasmic reticulum to generate muscle contraction

Elite Athletes and Lactate

It’s observed that elite athletes have superior athletic capacity compared to other athletes, with their ability to clear lactate being the most notable factor for physical performance.

Elite athletes can clear H+ from the blood at a faster rate

The lactate clearance process isn’t immediate and takes some time; plus, lactate keeps being produced as long as the activity continues

That’s why better-trained athletes are very efficient at reducing lactate buildup (clearing) in the blood before a new dose is produced

What is the Lactate Threshold?

The lactate threshold is the maximum intensity an athlete can maintain for a certain period without excessive fatigue forcing them to stop.

We can also define it as the lactate level or concentration in the blood “tolerable” by the person, meaning a pace where breathing can be maintained without gasping or feeling dizzy.

We relate the lactate threshold concept to the maximum metabolic stress that can be sustained for a set time

An athlete has a lactate threshold higher than most people; usually due to genetics, boosted by training

Lactic acid causes muscle pain, sharply increases breathing, and causes a drop in activity intensity to fix the oxygen debt

How to Improve the Lactate Threshold?

As we’ve seen, during exercise, fast contraction fibers generate lactate due to their glycolytic substrate. However, lactate is removed by slow contraction fibers, which have higher mitochondrial capacity and high levels of mLDH enzymes and MCT-1 transporters.

So, if your goal is to improve lactate threshold, it means boosting the ability to clear lactate (“lactate clear”), and the key is training Type I fibers (slow or oxidative) to stimulate growth and increase mitochondrial density, plus the related physiological complex.

Lactate threshold training: rowing is one of the sports activities we can use to improve this athletic condition

In muscle, metabolic stress increases with lactate and H+ buildup, where a key part of the cell, the mitochondria, suffers this stress due to the need to clear lactate quickly to support ongoing activity; otherwise, this organelle saturates, and lactate levels in blood skyrocket, causing effort to stop.

Example of Lactate Threshold Training

Let’s use as an example a aerobic lactate threshold training by world-class coach Chris Hinshaw, who weekly shares training plans to develop this and other aerobic capacities

Can Lactate Benefit Us?

Obviously, the first thing that comes to mind when hearing lactic acid or lactate (its accumulation) is a high-stress situation from an exhausting activity that causes “pain” to some degree, and that you’ll probably have to stop soon.

But, of course, that scenario changes depending on the source: it’s not the same for someone just starting to train as for someone who started as a kid and has kept that pace their whole life.

They’ve developed a huge adaptation and the results are clear:

They have a greater tolerance to effort than others, and
They can endure that situation for longer.

We could say they “have a higher lactate threshold”

Like any skill, it can be trained, and actually, despite the controversy, lactate can benefit our performance.

Lactate and Muscle Contraction

Certain studies, contrary to old beliefs, highlight that lactate can improve muscle contraction:

Muscle contraction happens thanks to electrical impulses generated in cell membranes, promoting potassium to move inside the cell and chloride ions to stay outside. However, during intense, vigorous exercise, potassium ions accumulate outside the cell.

As this buildup increases outside the cell, the electrical impulse weakens, and chloride ions prevent potassium from returning inside.

In this case, lactic acid removes chloride, allowing potassium to return inside the cell

Thus, lactic acid increases potassium ratio inside the cell environment, making muscle contraction more effective

From this, we can clearly conclude that our performance will be higher the better we can tolerate lactate

Lactate as Fuel

In terms of high performance, lactate might be the best fuel muscles can use. Just like muscles use different macronutrients for energy needs, an enzyme network provides the chemical reactions needed for this process.

However, a high percentage, around 80%, of energy for muscle supply is lost as heat

So, constantly generating new energy produces more heat, potentially saturating the muscle or failing to meet demand

The enzymes metabolizing these nutrients’ energy require oxygen, but during high intensity, it’s impossible to get enough oxygen for energy production, and hydrogen ions accumulate, acidifying muscles and blood flow.

This muscle buildup acidifies the fiber, forcing a reduction in power or intensity

Muscles don’t need much oxygen to convert lactate into energy. So, when lactate is produced, muscles can use it for energy with hardly any oxygen.

When the demanding activity decreases or stops, it’s possible to repay the oxygen debt and recover

You could say “the harder you push, the more lactate will help you…”

Beta-Alanine to Fight Lactate

In a way, supplementation aimed at improving performance tries to fight or quickly clear lactate concentration in the blood. Depending on how it works, you’ll find different types of products.

This is the case with Beta-Alanine. You can find it in powder or capsule form; and the way to take it is…

According to some studies, Beta-Alanine may help produce a buffering effect on lactate, allowing athletes to clear this substance from the blood. Beta-Alanine increases intramuscular carnosine concentration during muscle contraction.

Thanks to this buffering function, beta-alanine can reduce acidosis without affecting oxygen absorption.

As we’ve seen, lactate doesn’t seem to inhibit muscle contraction, which may be due to H+ ion buildup eventually inhibiting contraction and glycolysis.

Beta-Alanine can be combined with Creatine to boost performance effects. If you want to learn more about Creatine for performance, click here.