Real Talk about Lactic Acid

Quick Tip: The Truth About Lactic Acid & Distance Running

I really don’t have a lot of issues that just make me lose my mind, climb up on my soap box, and rant like a maniac.

If you listened to the Listener Q&A Episode from February, however, you know one issue that gets me hot under the collar in just a matter of seconds.

After that episode was released, a couple of folks from the Facebook group had some additional questions about said issue, so it only made sense to try and set the record straight today on the topic of lactic acid.

Real Talk about Lactic Acid

What is It?

Most runners have probably heard of lactic acid, but I’m not sure how many runners actually know what it is.

So let’s start there.

To try and keep things simple, cause this can get complicated quickly, lactic acid is a by product that is created during anaerobic energy production at the cellular level.

What Does It Do?

Lactic acid can actually be used by the body to create additional ATP (which is ultimately the thing that powers everything that our bodies do).

That process is not very efficient, but in short bursts of intense exercise it gets the job done.

The longer the duration of the exercise, however, the more lactic acid builds up within our muscles.

And that build of lactic acid causes one thing: muscle failure.


Lactic acid does not cause muscle soreness.

Please, allow me to say that again because I know at least one person glossed over that.


If you’ve been told that before, and I know that most of us have heard this running fable at some point along the way, please get that idea out of your mind.

Lactic acid is a byproduct of anaerobic energy production and has absolutely nothing to do with why your muscles are sore after running a marathon.


As in, not a damn thing!


(Sorry to be so dramatic, but I just want to make sure my point, aka the truth, is clearly communicated!)

You Know What Really Grinds My Gears…

I lose my mind when I see massage therapists or companies pitching their “recovery” products touting how their product or service helps to remove the lactic acid from your muscles, which will help to relieve your soreness after the race.

That is complete and utter bullshit.

Remember, the soreness you experience after a marathon, an interval session, a hard workout, or anything else has nothing to do with lactic acid. Nothing.

When you see that kind of marketing, you are being straight up lied to. No ifs, ands, or buts about it.

They are lying to your face and hoping that you don’t know what they are doing.

Now you do.

And to be clear, I’m not saying that a post-race massage (or compression, or ice, or any of the other products that could fall into this category) is a bad thing.

I’m not even saying that it won’t help to minimize your soreness after a race.

What I am saying is that their claim that the lactic acid in your body is going to cause you to be sore the next day, and that their product/service can help you remove the lactic acid, is a lie.

Let’s Talk Truth

During an easy run, your body produces virtually no lactic acid. If you’re running at a conversational pace, you are producing the energy you need aerobically, which does not produce lactic acid.

During a hard run, say a tempo run, you are running hard enough that your body is definitely creating some lactic acid but not so hard (if you’re pacing correctly) that it builds up and forces you to slow down (remember, lactic acid causes muscle failure).

During a hard run, like high speed intervals, you are creating lactic acid in your muscles which is why you’re hurting so badly after each hard effort. But after a brief recovery, you’re able to go again. Why? Because while you weren’t exercising as intensely your body was able to process and remove the built up lactic acid from your muscles!

That’s all well in good in a training run or a workout, but what about during a race?

If you’re running with the pedal to the medal in a race, no matter the distance, lactic acid build up can become a problem.

But most of us aren’t running an entire race with the pedal to the medal.

And if you’re running a marathon, you definitely aren’t.

Even at the highest levels, like the guys running 2:05s, they aren’t often running above a tempo pace. So they probably aren’t running above their lactate threshold.

And when they do go a little too fast at that level, they get dropped like a bad habit as soon as their blood lactate levels climb too high.

What You Need to Know

  1. Lactic acid does not cause muscle soreness. If you get nothing else from my blog, this post, my podcast, or anything else that I have ever created, please remember that!
  2. In endurance events like half/full marathons, unless you’re truly an elite or unless you go out WAY too fast, lactic acid build up is not something that should concern you on race day.
  3. Anyone trying to tell you they’ve got the secret to helping you get rid of lactic acid as a means to reducing any potential muscle soreness is trying to sell you something. And they are full of it and/or lying to you.

Period. End of story. That’s a wrap.

Thanks for coming out!

*Getting off the soap box*

Hope the rant helped. And if you haven’t already listened to the audio component of the quick tip, please go back to the top of this post and press play.

It’ll be worth it…

Learn the #truth about how Lactic Acid impacts runners. #runchat #runners Share on X

What Other Lactic Acid Related Questions Do You Have That I Can Help You With?

Adding this post to the link up hosted by some great running coaches and bloggers  Running on HappySuzlyfeCrazy Running Girl, and Coach Debbie Runs!