Is muscle soreness necessary for growth — or a sign you did something wrong?

Delayed-onset muscle soreness — the ache that shows up a day or two after a hard session — gets read two completely opposite ways. Some lifters chase it as proof a workout "worked." Others feel it and panic that they have injured themselves. A 2012 review in the Journal of Strength and Conditioning Research examined the actual biology behind the soreness to answer both fears at once.

Where soreness actually comes from

Brad Schoenfeld’s review explains that delayed-onset soreness is a symptom of exercise-induced muscle damage (EIMD), which occurs primarily from unaccustomed exercise, and is modulated by the type, intensity and duration of training. Eccentric contractions — the lengthening phase of a lift, like lowering a squat — cause by far the most damage, ranging from microscopic tears in individual muscle proteins up to larger tears in the surrounding connective tissue.

Is the damage actually required for growth?

This is where the review gets genuinely useful. One long-standing theory holds that the muscle damage and resulting inflammation are necessary signals for long-term hypertrophic adaptation — that the repair process itself is what triggers growth. But Schoenfeld is explicit that other researchers have directly challenged this idea, noting that meaningful hypertrophy can occur in the relative absence of muscle damage. In other words: soreness can accompany growth, but the research does not support treating it as a requirement for growth.

Hypertrophy can occur in the relative absence of muscle damage.

Why soreness fades even as your lifts keep improving

A big part of why soreness is such an unreliable indicator is the "repeated bout effect": the first time you do a new exercise, or return to one after time off, the unfamiliar stress causes real damage and real soreness. Do that same movement again a week later and your muscle has already adapted to handle it — soreness drops off fast even while your strength and size keep climbing. That is precisely why intermediate and advanced lifters, doing largely the same core movements week after week, are often barely sore at all despite still making steady progress.

The practical takeaway

Being sore does not mean a session "worked," and not being sore does not mean it failed. Sharp, acute pain during a lift, or pain that is asymmetric, joint-specific or worsening rather than fading over a few days, is a different signal entirely and worth getting checked by a professional — ordinary DOMS is diffuse, symmetric, and resolves within about 48–72 hours. Progressive overload, adequate weekly volume and consistent training are the levers that reliably drive results — soreness is, at best, a rough and unreliable side effect of some of them.

This is why Misi tracks your actual training variables — volume, proximity to failure, progression over time — rather than asking how sore you felt, and why the readiness check-in asks about fatigue and recovery rather than treating soreness itself as a target to chase.

Misi is a coaching and wellness platform, not a medical service. Persistent, sharp, or joint-specific pain should be assessed by a qualified professional rather than assumed to be normal soreness.