Lactic Acid: What It Really Is and What It Means for Your Workout
- Deion DeLeon
- 6 days ago
- 3 min read
By Deion DeLeon – Functional Fitness Professional
You've probably felt it before:
That burning sensation in your muscles during an intense set of squats, sprints, or high-rep pushups. You push through a few more reps, your legs feel like fire, and someone nearby says:
“That’s just lactic acid.”
But what exactly is lactic acid? Is it bad? Is it what causes soreness? And should you try to avoid it?
Let’s break it down—in the simplest way possible—so you can better understand what’s happening inside your body during your workouts.
What Is Lactic Acid?
Lactic acid is a temporary byproduct your body produces during intense exercise—especially when your muscles are working hard and oxygen is limited.
Here’s the quick science:
Your muscles use glucose (sugar) for energy.
When there's plenty of oxygen, that glucose is burned cleanly through a process called aerobic metabolism.
But during high-intensity training—like sprinting or lifting heavy—you need energy fast, and oxygen delivery can’t keep up.
So, your body switches to a faster method: anaerobic metabolism (without oxygen).
This produces a substance called lactate, along with hydrogen ions (H+), which cause the burn you feel.
Important note: 👉The term “lactic acid” is often used, but it’s really lactate that builds up—not acid. So technically, you’re not “feeling lactic acid,” you’re feeling the effects of lactate + hydrogen ions building up in the muscle.
Why Does It Burn?
The burn you feel during a tough set isn’t because lactate is hurting you—It’s because those extra hydrogen ions drop the pH in your muscles (making them more acidic), which interferes with muscle contractions and causes that burning fatigue.
Lactate actually helps you:
Continue producing energy
Delay complete muscle failure
Buffer some of that acidity
In other words, lactate is part of the solution, not the problem.
Does Lactic Acid Cause Muscle Soreness?
No.
This is one of the biggest myths in fitness.
That sore feeling you get 24–48 hours after a workout (a.k.a. DOMS—Delayed Onset Muscle Soreness) is not caused by lactic acid.
Instead, it’s from:
Tiny microtears in your muscles
Inflammation
Fluid shifts and cell damage from unfamiliar or intense movement
Lactate clears out of your system within 1–2 hours after exercise, so it’s long gone by the time soreness kicks in.
What Happens to Lactate After Your Workout?
Your body is smart.
Once the intensity drops and oxygen becomes available again, your body recycles lactate in a few keyways:
It’s used as fuel by your heart, brain, and muscles
It gets converted back into glucose (sugar) by your liver
It helps clear out the acidic byproducts from your muscles
This process is part of what’s called the Cori Cycle—your body’s way of restoring balance after anaerobic effort.
Why Lactic Acid Matters for Training
Lactate buildup is a signal that you're pushing into a higher intensity zone. That’s where a lot of progress happens—cardio endurance, strength, power, and metabolic conditioning.
By training smartly in this zone, you can improve your body’s ability to:
Tolerate lactate buildup
Clear it more efficiently
Perform better for longer
This is why athletes do interval training, HIIT, and tempo work—to push their lactate threshold higher.
How to Manage Lactate Buildup (And Improve Your Workouts)
Here’s how to get better at handling that burn and bouncing back faster:
1. Train with Intention
Don’t avoid the burn—learn to work with it. Incorporate interval work, supersets, and controlled tempo lifts to challenge your anaerobic system.
2. Breathe Through It
Deep, controlled breathing during effort helps get more oxygen to your muscles—and clears waste faster.
3. Stay Hydrated
Water helps buffer acids in the body and keeps blood flow high for lactate transport.
4. Active Recovery > Doing Nothing
After an intense workout, light movement (like walking, stretching, or cycling) helps remove lactate more efficiently than total rest.
5. Fuel Your Body Right
Eat enough carbohydrates to maintain energy levels and give your muscles what they need to recover and rebuild.
Final Thoughts: The Burn Isn’t the Enemy
Feeling the burn during a tough set? That’s your body adapting, pushing you toward growth.
Lactate is not something to fear—it’s a sign you’re working, and your body is rising to the challenge.
But now, you understand why it happens, what it means, and how to recover smarter.
At Deion DeLeon Functional Fitness, I help clients train with more than just effort—I teach them the science behind the sweat, so they can train smarter, not just harder.
📲 Ready to push past your limits—and recover like a pro?
DM me “BURN SMART” Instagram @deion_deleon217
📅 Or schedule your free consult today
Let’s turn the burn into real results.
Comentários