DOMS, Explained: What Soreness Does and Doesn't Mean
Soreness mostly tracks unfamiliar eccentric load, not muscle damage or growth. What it actually signals.
Delayed onset muscle soreness — DOMS — is the stiffness and tenderness that shows up a day or two after a hard session, especially a new one. It’s so reliably present after tough training that many people treat it as a scorecard: more soreness, better workout. That intuition is mostly wrong, and untangling what DOMS does and doesn’t mean is genuinely useful for how you train.
What DOMS actually reflects
DOMS follows unfamiliar or eccentric-heavy exercise — the lowering phase of a lift, or a movement your body isn’t adapted to. It appears after a pain-free period of 12–24 hours, peaks at 24–72 hours, and resolves within about seven days. The long-held assumption was that the pain simply mirrors microscopic muscle damage. A 2024 review in The Journal of Physiological Sciences by Mizumura and Taguchi complicates that picture: in their experimental work, DOMS-like sensitization developed under conditions without measurable muscle damage, with histological necrosis appearing only at extreme exercise intensities.
Their proposed mechanism is neurochemical rather than structural — a bradykinin-driven rise in nerve growth factor (NGF) and a separate COX-2/GDNF pathway that sensitize the muscle’s pain fibers, with NGF upregulation confirmed in humans roughly 24 hours after eccentric contractions. In other words, soreness reflects how your nociceptors were sensitized, not a clean readout of injury or adaptation.
The other key word is unfamiliar. After a single bout, the muscle rapidly adapts so the same workout produces far less soreness — the well-documented “repeated bout effect.” That alone shows why soreness is a poor progress gauge: a beginner doing an easy novel exercise can be wrecked, while a trained lifter doing a genuinely hard session feels little.
Soreness mostly tracks novelty and eccentric load — and how your pain fibers were sensitized — not how much you grew or how effective the session was. A workout that builds strength and one that just makes you sore are not the same thing.
What to take from soreness levels
- High soreness from a new movement: expected, not a sign of a superior workout.
- Little soreness from a familiar, hard session: completely normal, and not a sign you under-trained.
- Soreness that’s severe, lingers many days, or comes with dark urine: a reason to back off and, if extreme, seek medical advice — this can signal excessive damage.
Training around it, briefly
Because soreness isn’t a reliable feedback signal, it’s a poor variable to chase or to base your whole program on. Track things that actually map to progress — loads, reps, performance over weeks — and let soreness be context, not the verdict. Modest soreness is fine; it doesn’t need treating beyond light movement and time.
The takeaway
DOMS signals that you did something your muscles weren’t used to, not that you did something productive. Don’t seek it out as proof of effort, and don’t be discouraged when an effective session leaves you feeling fine. The body adapts, and a fading tendency to get sore is a sign that adaptation is working exactly as it should.