How do I tell if I'm sore or injured?

Sore or Injured? Quick Tests to Know the Difference

Muscle ache two days after hill repeats is almost a badge of honour, but a sharp twinge that hijacks
your stride can signal trouble. Confusing the two leads to either unnecessary rest or, worse, a
blown‑up injury. Distinguishing sore from injured is a skill rooted in tissue biology, pain science
and a handful of simple at‑home assessments.

This 800‑word introduction frames the decision process. First, we explore how delayed‑onset muscle
soreness (DOMS) develops eccentric micro‑tears that heal stronger, while structural injuries—tendon
strains, bone stress reactions—show distinct pain signatures. You’ll learn why DOMS is diffuse and
bilateral, peaking 24‑48 hours post load, whereas injury pain localises, sharpens with activity and
may worsen overnight.

We then preview the objective checks—range‑of‑motion asymmetry, single‑leg hop tolerance, manual
strength tests—that turn gut feel into evidence. By the end, you’ll have a repeatable 5‑minute
protocol to decide whether to lace up, cross‑train or call a physio.

Pain Profile: Location, Onset, Intensity & Trend

**Location:** DOMS spreads across a whole muscle group (both quads); injuries pinpoint a tendon or
bone ridge. **Onset:** DOMS surfaces 6–12 h post‑exercise; injuries can be immediate or escalate
during the run. **Intensity Curve:** DOMS pain scores 2–4/10 and eases with gentle movement; injury
pain may start mild but climbs, surpassing 5/10 and altering gait. **Trend:** DOMS fades after 72 h;
injury pain lingers or intensifies.

Red‑flag combos: night pain that wakes you, swelling, bruising, audible pops, or inability to bear
weight—these shift probability sharply toward injury.

Decision Tree: Rest, Modify or Rehab & Return

**Range‑of‑Motion Test:** Compare injured vs. uninjured side—20 percent suggests injury. **Single‑Leg Hop:** Perform three hops; pain ≥3/10 or poor landing control indicates structural issue. **Isometric Strength:** Push against immovable object—if force feels 20 percent weaker or evokes sharp pain, suspect strain. Tendon screen: morning calf raises—painful first steps point to Achilles tendinopathy. Bone stress screen: hop test on tibia; sharp, local pain on impact flags stress reaction. For a full injury symptom checklist, visit WebMD.

**Green Light (DOMS):** Pain ≤4/10, symmetric, ROM deficit 5/10, focal, increasing, or hop/strength fails. Rest 48 h, start POLICE, and book professional assessment. Log pain scores alongside HRV in the Endurance App; two consecutive high pain‑low HRV days trigger an automatic rest alert. Study form drills in why is running so painful to correct mechanics once pain subsides—poor technique often seeds repeat injuries. Master this decision tree and each ache becomes a data point guiding smarter, safer progress.