Why Do Muscles Get Sore? Understanding Muscle Soreness

Have you ever finished a tough workout, only to wake up the next day feeling stiff, achy, and wondering why your muscles are sore? Muscle soreness is a common part of training, yet it can leave many confused about what it really means and how it happens.

What Does Muscle Soreness Mean?

Muscle soreness, often referred to as Delayed Onset Muscle Soreness (DOMS), is the discomfort or stiffness you feel in your muscles after unfamiliar or intense physical activity. It typically peaks between 24 to 72 hours after exercise and gradually subsides as your muscles recover and adapt.

What Causes Muscle Soreness?

The primary cause of muscle soreness is microscopic damage to muscle fibers during exercise, especially when performing eccentric movements (lengthening under tension, like lowering a dumbbell). This damage triggers an inflammatory response, drawing fluids and nutrients to the area to repair the tissue, which contributes to swelling, tenderness, and that tight, sore feeling.

In simpler terms, soreness indicates your body is responding to a new or intense challenge by repairing and rebuilding your muscles to become stronger.

Why Do We Feel Sore?

When your muscles experience this tiny damage, nerve endings in the affected area become sensitized, leading to the ache you feel. It is your body’s way of signaling that it is healing and adapting.

Why Am I More Sore Than Usual?

You may feel more sore than usual if:

• You increased the intensity, volume, or duration of your workout.

• You introduced new exercises or movement patterns.

• You returned to exercise after a break.

• Your recovery habits (hydration, sleep, nutrition) were insufficient.

Feeling sore is not always a sign of an effective workout, but it can indicate that your muscles are encountering a new stimulus.

How Do Muscles Get Sore?

Muscles get sore when:

• They undergo eccentric contractions (lengthening while under load).

• They experience microtears in muscle fibers.

• The repair process causes inflammation, which increases pressure and sensitivity in the tissue.

Does Muscle Soreness Mean You’re Building Muscle?

Muscle soreness is not a requirement for muscle growth, but it often accompanies the process when your muscles are challenged in a new way. Consistent training, progressive overload, and proper recovery are what lead to muscle growth, regardless of soreness levels.

Personal Note on Muscle Soreness

I remember training for my first pull-up progression phase after years of weightlifting. Despite being active, I underestimated the intensity of slow negatives (eccentric pull-ups) and woke up the next day unable to straighten my arms without wincing. It taught me the importance of progressing gradually and respecting the body’s signals. Soreness was a reminder that I was pushing into new territory, but it also taught me that recovery practices—hydration, mobility work, and adequate protein—make all the difference in how quickly soreness resolves.

How to Manage and Reduce Muscle Soreness

While you can’t always avoid soreness, you can manage it:

• Active recovery: Light movement, walking, or gentle stretching can increase blood flow.

• Hydration: Supports nutrient delivery and waste removal.

• Proper nutrition: Protein and antioxidants aid in repair.

• Rest and sleep: Crucial for muscle recovery.

• Massage or foam rolling: Can help reduce tightness and discomfort.

Final Thoughts

Muscle soreness is a natural response to challenging your body in new or more intense ways. It means your muscles are adapting, repairing, and getting stronger. However, listen to your body, progress gradually, and remember that soreness is just one small piece of your overall fitness journey—not the sole indicator of progress.