intense workout that can cause lactic acid buildup

Does Lactic Acid Cause Soreness? Here’s Everything You Need to Know

Do you ever feel really sore after a workout? Like, so sore that you can hardly move?

For years, the fitness community - even credible scientists - blamed lactic acid buildup.

Lactic acid is a natural byproduct of muscle activity that builds up in your muscles during intense exercise.

It's this buildup that was thought to cause the delayed-onset muscle soreness that you tend to feel after a tough workout.

But is that still the case?

In this blog post, we'll discuss what lactic acid is, why it builds up in your muscles, and whether lactic acid buildup is the reason for sore muscles.


What is Lactic Acid?

Lactic acid is an organic compound that is produced when your body breaks down glycogen for energy during exercise.

Lactic acid is a completely natural and normal byproduct of exercise, and it doesn't cause any harm.

In fact, lactic acid is used by your muscles as fuel!

When your muscles burn glycogen, lactic acid is the result and this is used by muscles for energy.


What Causes Lactic Acid Buildup?

Continuing with the point above, we know that muscles burning glycogen for fuel produces lactic acid buildup. But what exactly causes muscles to burn glycogen?

In one word: intensity.

The more intense your workout, the more glycogen your muscles will burn.

And the more glycogen that's burned, the more lactic acid will build up in your muscles.

This doesn't mean you have to go from a simple walk around the block to training for a triathlon.

Lactic acid buildup usually happens when your workout is outside of your normal routine.

For example, if you normally walk for 30 minutes a day, and then one day you go for a run instead, lactic acid will build up in your muscles because your body isn't used to the extra activity.

It's a small change, but it's big enough for your body to need the extra fuel. The result is more lactic acid buildup.


Does Lactic Acid Buildup Cause Sore Muscles?

Now, the million-dollar question: Does lactic acid buildup cause sore muscles?

Despite decades of many people believing otherwise, the answer is, "NO!"

Lactic acid buildup does NOT cause sore muscles.

As we discussed above, lactic acid is the normal byproduct of exercise, and it acts as a reliable fuel source for muscles pushed outside of their comfort zone.

If lactic acid doesn't cause sore muscles... what does?


What Causes Sore Muscles?

When you pick up a weight and use it for any number of exercises - presses, curls, squats - there's a lot going on within the muscle tissue.

Most notably, your muscle tissue is experiencing microtrauma and microtears.

This sounds worse than it actually is.

Microtears are a good thing, especially if you want to get stronger and have bigger muscles.

But those gains come at a cost. And that cost is muscle soreness.

Remember that cliché fitness saying, "No pain, no gain?"

Well, there's some truth to that. You wouldn't want to break a bone or strain a muscle - We're not talking about that kind of pain.

But if you're appropriately sore following a workout, then that means you did your job.


How to Get Rid of Muscle Soreness?

The question is not “how do I get rid of lactic acid buildup.” Rather, you should be asking, “how do I get rid of muscle soreness?”

Here are some ways you can reduce your muscle soreness.



Dehydration can make muscle soreness stick around for much longer than it needs to so drink plenty of water!

Even if you’re not sore, you should be consuming about a gallon of water per day. This is a broad estimate, but a decent rule of thumb to stick by.

Sometimes you may not be able to access that much water, this is when electrolytes  help you hydrate properly.

Ice and Heat

What you’re experiencing is a type of inflammation, and one of the easiest ways to reduce that is to apply ice to the sore muscle. We recommend doing that for 10 to 15 minutes every few hours.

You can complement this by applying a heating pack to improve nutrient-carrying blood flow to the muscles.

Focus on ice first to reduce the inflammation and then later on, try a heating pad.


Get a Massage

It won’t be the most pleasant massage you’ve ever had, but a massage – especially a sports massage – is a great way to speed up recovery.

If you don't want to drop the money on a massage, you can always grab a lacrosse ball to use for a massage

Over-the-Counter Medications

If the soreness is interfering with everyday life, you might want to consider using an NSAID (non-steroidal anti-inflammatory drug) like ibuprofen.

Just be sure not to overdo it. Most NSAIDs caution that you shouldn’t use more than two servings per day.


How to Prevent Muscle Soreness

If you're loose and limber now, and you want to stay that way, here are a few things you can do to avoid extreme muscle soreness.



Do a light warm-up before your workout. This will help prepare your muscles for the activity and reduce the severity of the muscle soreness.



Once you finish with the workout, do a cool-down. This is usually hardest part for most people because it’s not exciting and you’re itching to leave the gym. Trust us, this will help your muscles recover and reduce how sore you are the next day.


Foam Roll

As a part of your cool-down, we would recommend foam rolling. This is a great way to massage your muscles, break up muscle adhesions (knots), and reduce muscle soreness.


Progress at a Reasonable Pace

Avoid doing too much too quickly. Gradually increase the intensity of your workouts. If you're just starting out, don't go from 0 to 100. Build up gradually so that your muscles can adapt to the extra activity.


Listen to Your Body

If you're feeling pain or discomfort, stop what you're doing and rest. Pushing through the pain will only make things worse.


Be Consistent

Above all, be consistent with your training. People who experience the worst muscle soreness are usually just starting out in the weight room or exercise class.

But over time, as long as you continue working out, you’ll notice that the soreness gradually fades to a dull ache that you barely notice.