When Is Muscle Soreness Normal—and When Is It an Injury?

If you have ever started a new workout, increased your training intensity, or returned to

exercise after time away, you may have experienced muscle soreness afterward. But

how do you know whether that soreness is a normal part of recovery—or a sign that you

have actually injured yourself?

The answer is not always obvious. Delayed-onset muscle soreness (DOMS) is a normal

response to unfamiliar or strenuous exercise, but muscle strains and other injuries can

also cause pain and tenderness. Understanding the differences can help you make

better decisions about exercise, recovery, and when to seek professional care.

What Is Normal Muscle Soreness?

Delayed-onset muscle soreness, commonly called DOMS, typically develops after

unfamiliar or strenuous physical activity. It can involve muscle soreness, stiffness,

temporary reductions in strength and physical performance, and sometimes swelling.

DOMS is particularly common after activities involving substantial eccentric muscle

contractions, such as lowering weights, running downhill, or performing exercises your

body is not accustomed to.¹

Unlike an acute injury, DOMS generally does not begin as a sudden, sharp pain during

the activity itself. Instead, you may feel relatively normal immediately after exercising

and then notice increasing soreness over the following day or two.

For example, you might complete a new leg workout on Monday and notice that your

thighs are increasingly sore when walking downstairs on Tuesday or Wednesday. If the

soreness then gradually improves, that pattern is consistent with DOMS.

Systematic-review evidence also shows that exercise-induced muscle damage can

temporarily affect strength and athletic performance. A 2024 systematic review and

meta-analysis found that resistance and plyometric exercise significantly impaired sprint

and change-of-direction performance for up to 72 hours after exercise.²

What Does an Injury Feel Like?

A muscle injury, such as a strain, tends to have a different presentation.

Traumatic muscle injuries can occur when high forces or strains are placed on muscle

tissue, particularly during muscle activation while the muscle is lengthening. Diagnosis

is generally based on the person's history and physical examination, with imaging used

when appropriate.³

Warning signs that may suggest an injury include:

● Sudden or sharp pain during exercise

● A popping or snapping sensation

● Pain that immediately causes you to stop an activity

● Significant swelling or bruising

● Noticeable weakness

● Difficulty using the affected muscle or putting weight on a limb

● Pain that continues to worsen rather than gradually improve

● Persistent pain that interferes with normal activities

These symptoms do not necessarily mean you have a serious injury, but they are

reasons to consider an evaluation rather than simply trying to exercise through the pain.

Research involving acute hamstring injuries has found that clinical factors such as pain

at the time of injury, bruising, and other examination findings can help clinicians

evaluate injury severity and prognosis.⁴,⁵

DOMS vs Muscle Injury: What Is the Difference?

A useful way to think about the distinction is timing, sensation, and function.

Normal post-exercise soreness

• Usually develops several hours after exercise

• Often becomes most noticeable during the following 1–3 days

• Typically affects muscles that were recently challenged

• Often feels achy, stiff, or tender

• Generally improves over time

• May temporarily reduce strength or physical performance

Possible muscle injury

• May occur suddenly during activity

• Can cause sharp or localized pain

• May be accompanied by bruising or swelling

• Can produce significant weakness

• May change how you walk, run, lift, or move

• May fail to improve or may become worse

There is some overlap between the 2 conditions, which is why pain alone cannot always

determine whether an injury has occurred. DOMS and other forms of exercise-related

muscle pain can share symptoms, making clinical context and physical examination

important when the diagnosis is uncertain.¹,³

Should You Exercise When You Are Sore?

If you are experiencing ordinary DOMS, you generally do not need to remain completely

inactive. Light movement may be appropriate as your muscles recover, provided it does

not significantly increase your symptoms or alter your normal movement.

However, pain is not something you should automatically push through.

If a particular movement produces sharp pain, causes you to compensate with another

part of your body, or significantly increases your symptoms, stop that activity and

consider getting evaluated.

Recovery strategies can also vary in effectiveness. A systematic review and

meta-analysis of postexercise recovery techniques found that several

interventions—including massage, active recovery, cold-water immersion, and other

strategies—may influence soreness or markers of muscle damage, but their

effectiveness varies depending on the intervention and outcome being measured.⁶

More recent evidence continues to demonstrate that there is not one universally

effective treatment for DOMS. A 2025 umbrella review of systematic reviews found

evidence supporting some interventions at specific time points, but also highlighted

substantial heterogeneity and the generally low methodological quality of many existing

systematic reviews.¹

Therefore, recovery should be individualized rather than based on the assumption that

one treatment works for everyone.

When Should You See a Physical Therapist?

Consider seeing a physical therapist if you are unsure whether your symptoms

represent normal soreness or an injury—particularly if pain is affecting your ability to

walk, exercise, work, sleep, or perform everyday activities.

A physical therapist can evaluate movement, strength, range of motion, and symptoms

to help determine what may be contributing to your pain. For suspected muscle injuries,

clinical assessment commonly includes a detailed history and physical examination,

with imaging used when appropriate.³

Physical therapy can also be useful when soreness or pain keeps returning. Rather than

simply treating the symptoms, a physical therapist can help identify potential

contributing factors and develop a progressive plan to restore strength, mobility, and

function.

For acute hamstring injuries, for example, systematic-review evidence suggests that

rehabilitation involving progressive loading and lengthening exercises can improve

return-to-sport outcomes compared with some other approaches.⁷

The Bottom Line

Muscle soreness after a challenging or unfamiliar workout is often a normal part of your

body's response to exercise. DOMS typically develops after the activity and gradually

improves as your body recovers.¹

Pain that occurs suddenly during exercise—especially when accompanied by swelling,

bruising, weakness, a popping sensation, or loss of function—is more concerning for a

muscle injury.³

The key differences are often when the pain begins, how it feels, whether there are

visible or functional changes, and whether symptoms improve over time.

When you are unsure, you do not have to guess. A physical therapy evaluation can help

determine what may be causing your symptoms and guide you toward a safe return to

the activities you enjoy.

References

1. Wiecha S, Cieśliński I, Wiśniowski P, et al. Physical therapies for delayed-onset

muscle soreness: an umbrella and mapping systematic review with

meta-meta-analysis. Sports Med. 2025;55(5):1183-1212.

doi:10.1007/s40279-025-02187-5

2. Harrison DC, Doma K, Rush C, Connor DJ. Acute effects of exercise-induced

muscle damage on sprint and change of direction performance: a systematic

review and meta-analysis. Biol Sport. 2024;41(3):153-168.

doi:10.5114/biolsport.2024.131823

3. Edouard P, Reurink G, Mackey AL, et al. Traumatic muscle injury. Nat Rev Dis

Primers. 2023;9(1):56. doi:10.1038/s41572-023-00469-8

4. Reurink G, Goudswaard GJ, Tol JL, et al. Therapeutic interventions for acute

hamstring injuries: a systematic review. Br J Sports Med. 2012;46(2):103-109.

doi:10.1136/bjsports-2011-090447

5. Freckleton G, Pizzari T. Risk factors for hamstring muscle injury in sport: a

systematic review and meta-analysis. Br J Sports Med. 2013;47(6):351-358.

doi:10.1136/bjsports-2011-090664

6. Dupuy O, Douzi W, Theurot D, Bosquet L, Dugué B. An evidence-based

approach for choosing post-exercise recovery techniques to reduce markers of

muscle damage, soreness, fatigue, and inflammation: a systematic review with

meta-analysis. Front Physiol. 2018;9:403. doi:10.3389/fphys.2018.00403

7. Pas HI, Reurink G, Tol JL, Weir A, Winters M, Moen MH. Efficacy of rehabilitation

(lengthening) exercises, platelet-rich plasma injections, and other conservative

interventions in acute hamstring injuries: an updated systematic review and

meta-analysis. Br J Sports Med. 2015;49(18):1197-1205.

doi:10.1136/bjsports-2015-094879