That stiff, achy feeling that shows up a day or two after a tough workout has a name — delayed onset muscle soreness, or DOMS — and understanding what’s actually happening can help you manage it more effectively and know when it’s a normal response versus something more concerning. Here’s a complete breakdown.
What Is DOMS?
Delayed onset muscle soreness is a type of muscle discomfort that typically develops 12 to 24 hours after exercise, peaks around 24 to 72 hours post-exercise, and then gradually resolves, generally within 5 to 7 days. It’s especially common after unfamiliar exercise, a significant increase in training intensity or volume, or exercise involving a lot of eccentric muscle contractions (the lengthening phase of a muscle under load, such as the downward portion of a squat or the lowering phase of a bicep curl).
What Causes DOMS?
The exact mechanisms behind DOMS are still being researched, but the leading explanation involves microscopic damage to muscle fibers and surrounding connective tissue during unfamiliar or particularly demanding exercise. This microtrauma triggers an inflammatory response as part of the body’s natural repair process, which is thought to contribute to the pain and stiffness experienced in the following days.
Contrary to a long-standing popular myth, DOMS is not caused by lactic acid buildup — lactic acid (or more precisely, lactate) is cleared from muscles within an hour or so after exercise, long before DOMS symptoms typically even begin.
The “Repeated Bout Effect”
One of the more interesting aspects of DOMS is what’s known as the repeated bout effect: after experiencing DOMS from a particular type of exercise, subsequent sessions of that same or similar exercise tend to produce significantly less soreness, even at the same or higher intensity. This adaptation can last for several weeks to months and is part of why DOMS is often most pronounced when starting a new exercise program or significantly changing your routine, rather than being a constant feature of regular training.
Is DOMS a Sign of a “Good Workout”?
Not necessarily — the absence of significant soreness doesn’t mean a workout wasn’t effective, and conversely, seeking out DOMS as a marker of workout quality can actually lead to counterproductive training decisions, such as excessive training intensity without adequate recovery. As your body adapts to a consistent training routine (via the repeated bout effect), you can continue making progress with progressively less soreness over time.
Strategies That May Help Manage DOMS
Light activity and movement. Gentle movement, such as walking or light cycling, may help reduce the perception of stiffness, though it doesn’t appear to accelerate the underlying muscle repair process itself.
Gradual progression in training. Increasing exercise intensity, duration, or novel movements gradually, rather than making sudden significant jumps, can help minimize the severity of DOMS when trying new exercises or programs.
Adequate protein intake and sleep. Both support the body’s natural muscle repair processes, which are the actual underlying mechanism for DOMS resolution.
Massage. Some research suggests massage may modestly reduce the perceived severity of DOMS, though effects on the underlying muscle damage itself are less clear.
Anti-inflammatory approaches. While over-the-counter anti-inflammatory medications can reduce DOMS-related discomfort, some research suggests they might also slightly blunt certain adaptive processes related to muscle repair and growth when used very frequently — an area still being studied, worth discussing with a healthcare provider if you rely on these regularly for exercise-related soreness.
What Doesn’t Reliably Prevent or Treat DOMS
Despite popular belief, stretching before or after exercise has not been consistently shown to prevent or meaningfully reduce DOMS in research. Similarly, while staying well-hydrated is generally good practice, hydration itself hasn’t been shown to specifically prevent or treat DOMS.
When DOMS Might Be Something More
While DOMS is a normal, expected response to unfamiliar or demanding exercise, certain signs warrant medical attention rather than being dismissed as ordinary soreness: severe pain disproportionate to the exercise performed, dark urine (which can indicate a rare but serious condition called rhabdomyolysis, involving significant muscle tissue breakdown), or swelling and soreness that doesn’t improve or worsens significantly beyond the typical week-long timeline.
The Bottom Line
DOMS is a normal, temporary response to unfamiliar or unusually demanding exercise, driven by microscopic muscle damage and the resulting inflammatory repair process — not lactic acid buildup, despite the persistent myth. While various strategies can modestly ease the discomfort, gradual training progression and consistency remain the most effective ways to minimize its severity over time through the body’s natural adaptive response.
This article is for informational purposes only and is not a substitute for professional medical advice.
