The Truth About Lactic Acid and Muscle Soreness
Is Lactic Acid Really Causing Your Muscle Soreness?
One of the most common things I hear in my massage practice is:
“I must have a lot of lactic acid built up.”
For years, many of us were taught that sore muscles after exercise were caused by lactic acid accumulating in the body. It’s a simple explanation—but modern research tells a different story.
The truth is that lactic acid is not responsible for the muscle soreness you feel one or two days after a hard workout.
In fact, lactate plays an important role in helping your body produce energy.
What Is Lactate?
During exercise—especially as the intensity increases—your muscles need energy quickly.
As your body works to meet those energy demands, it produces lactate. Rather than being a useless waste product, lactate can serve as a valuable fuel source. Your heart, brain, and muscles can use it for energy.
Most lactate is cleared from the bloodstream relatively quickly after exercise. It does not remain trapped in your muscles for days, causing soreness.
In other words, lactate is not the villain it was once thought to be.
So Why Am I Sore?
The soreness that develops 24 to 72 hours after exercise is known as Delayed Onset Muscle Soreness (DOMS).
DOMS commonly occurs after:
Starting a new exercise program
Increasing workout intensity
Returning to exercise after a break
Hiking downhill
Strength training
Taking a long bike ride
Skiing or snowboarding
Doing any activity your body isn’t fully adapted to
Exercise creates microscopic stress within the muscle fibers and surrounding connective tissues.
Your body responds by beginning a natural repair and adaptation process. This response can lead to stiffness, tenderness, reduced range of motion, and soreness for a few days.
While it may be uncomfortable, mild to moderate soreness is often a normal part of how the body adapts and becomes stronger.
What Does This Mean for Massage?
Many people seek massage because they’re sore after exercise, and massage can be a wonderful tool for recovery.
However, it’s important to understand what massage is actually doing.
Massage isn’t “breaking up” or “flushing out” lactic acid.
Instead, massage may help by:
Reducing muscle tension
Supporting relaxation
Decreasing the perception of pain
Temporarily improving local blood flow
Encouraging body awareness
Helping you move more comfortably
Massage supports your body’s natural recovery process rather than removing stored lactic acid.
Many clients report feeling less stiff, moving more freely, and returning to the activities they enjoy with greater comfort after a massage.
Should You Be Worried About Soreness?
Not necessarily.
Mild to moderate soreness after a challenging activity is often a normal sign that your body is adapting to a new demand.
That said, pain is different from soreness.
Consider consulting a healthcare professional if you experience:
Sharp or sudden pain
Significant swelling
Joint pain
Loss of strength
Numbness or tingling
Pain that continues to worsen
The Takeaway
The next time someone tells you that sore muscles are caused by lactic acid, you can gently share a different perspective.
Lactate isn’t the cause of delayed muscle soreness. It is actually an important part of your body’s energy system.
The soreness you feel after a tough workout is generally related to the body’s natural repair and adaptation process as it works to become stronger, more resilient, and better prepared for future activity.
And that’s a pretty remarkable thing.
Whether you’ve spent the weekend hiking Colorado trails, biking mountain passes, gardening, skiing, snowboarding, or lifting weights, remember that recovery is an important part of progress.
Massage won’t “flush out lactic acid,” but it may reduce soreness and stiffness, support relaxation, and help you move more comfortably as your body recovers.
Be kind to your body—it is always working hard on your behalf.