Is Soreness an Indicator of a Good Workout?

What Muscle Soreness Actually Is

The muscle soreness you feel a day or two after a workout has a name: delayed onset muscle soreness, or DOMS. It typically takes 24 to 48 hours to develop and peaks somewhere between 24 and 72 hours after exercise. Any significant soreness that lingers longer than about five days can be a sign of muscle damage beyond what’s useful. More on that later.

It’s Not the Lactic Acid

So what actually causes DOMS? There’s a stubborn myth that lactic acid is the culprit. It isn’t. A classic piece of research on runners showed no meaningful soreness after high-intensity running on flat ground (which produces a lot of lactic acid), while the same runners got significantly sore after low-intensity downhill running, which produces very little. Lactic acid clears from your muscles within an hour or so of finishing. It’s long gone by the time DOMS shows up.

So why did downhill running cause more soreness? Because running downhill requires a large amount of lengthening, or eccentric, muscle contraction to resist the pull of gravity. A lengthening contraction is simply a muscle resisting a stretch. When you perform a bicep curl and lower the dumbbell from your shoulder back down to your side, that lowering is the lengthening portion of the exercise.

Now for the counterintuitive part: during the lengthening phase you actually recruit fewer muscle fibers than during the shortening phase (lifting the weight up). So if it takes 100 fibers to lift a weight, it might take only 80 to lower that same weight. Same load, fewer fibers doing the work, which means more force per fiber, and that’s what leads to the tiny mechanical disruptions, the inflammation, and finally the soreness.

It’s worth adding a modern footnote here. Newer research has questioned whether the pain even originates in the muscle fibers themselves, or partly in the connective tissue (fascia) surrounding them. One 2021 review went so far as to ask whether DOMS is a “false friend,” a sensation we’ve long assumed reflects muscle damage but that correlates poorly with the standard markers of it. Either way, the practical point holds: what you feel the next day is a rough, noisy signal, not a precise readout of what happened inside the muscle.

Does Soreness Mean Muscle Growth?

This is the question I get more than any other, so let’s answer it plainly: no, soreness is not a requirement for muscle growth, and it’s not a good measure of it either. You can build muscle and get stronger without being wrecked the next day, and you can be crushingly sore from a workout that did very little for your long-term progress.

Some research shows that roughly a third of people don’t experience much DOMS at all when following heavy, lengthening-based lifting programs, yet they still see the adaptations we care about, like muscle growth, strength, and endurance. If soreness were the price of admission for results, those people wouldn’t be getting stronger. They are.

The reason is simple. Soreness mostly reflects how unfamiliar a movement was, how much eccentric load it involved, and how sensitive you personally are. Muscle growth, on the other hand, is driven by progressively challenging your muscles over time and giving them enough recovery, protein, and total training volume to adapt. Those two things overlap sometimes, but they are not the same measurement.

So if you finished a solid session and you’re not sore the next morning, don’t panic and don’t assume you wasted your time. A lack of soreness usually just means the workout was within your body’s current capacity, which is exactly where a lot of productive training happens. The better questions to ask are: are the weights, reps, or distances trending up over weeks and months? Am I recovering well between sessions? Those tell you far more about progress than how much you groan getting out of bed.

How Much Soreness Is Enough?

This varies for everyone, and the honest answer is that you need very little. Severe DOMS isn’t essential to anyone’s fitness goals. That said, some people (myself included) genuinely enjoy a moderate level of soreness after training. A little muscle soreness that lasts no more than about 72 hours and doesn’t interfere with your daily life isn’t necessarily doing anything for you physiologically, but it isn’t hurting you either. Think of it as a neutral side effect, not a target.

The problems start when soreness becomes excessive. Not only does extreme soreness fail to equal a better workout, it can actively delay you from reaching your goals. Use the guide below to read where your soreness falls.

The Hidden Cost of Being Too Sore

If you’re so sore that you can’t train for three days and struggle with everyday tasks, your total daily energy expenditure drops. You take fewer steps, fidget less, skip the stairs, and generally move less throughout the day. This is a real, studied phenomenon called a reduction in non-exercise activity thermogenesis, or NEAT. That’s the calories you burn doing everything that isn’t formal exercise. When soreness quietly shuts your NEAT down, the energy-balance benefit you earned in the gym can be erased outside of it.

And in genuinely severe cases, the muscle can be damaged so much that critical internal structures leak out of the cell. When that happens, the muscle can be temporarily rendered incapable of adapting the way you want it to. More soreness, in other words, can mean less progress, the opposite of what the “no pain, no gain” crowd assumes.

Should You Work Out When You’re Sore?

Most of the time, yes, with some common sense applied. Mild to moderate soreness is not a reason to skip the gym. In fact, gentle movement usually helps it (see the next section). The goal is to train in a way that works with your recovery instead of digging a deeper hole.

Here’s a simple framework for deciding what to do on a sore day:

• Mildly sore, moving normally? Train as planned. If the sore muscles are the ones on the schedule, a proper warm-up often makes them feel better, not worse.
• Sore in one area? Work something else. If your legs are trashed, train upper body or core. This is one of the best reasons to rotate muscle groups across the week.
• Quite sore and it’s the same muscles again? Go lighter, cut the volume, or make it an active-recovery day. You don’t have to choose between “full session” and “nothing.”
• Still severely sore after 2–3 days? That’s your body asking for more recovery. Rest the area, keep moving gently elsewhere, and dial back the load that got you there.

How to Reduce Soreness (DOMS)

Severe DOMS isn’t a badge of honor, so there’s no reason not to blunt it. A few evidence-informed additions to your routine can meaningfully reduce how sore you get and how long it lasts.

Move, Don’t Just Rest

The most effective thing on this list is also the simplest: move. A light warm-up, such as five minutes on an elliptical, followed by low-intensity bodyweight exercises (squats, lunges, push-ups) and some easy stretching increases blood flow to the sore tissue and helps the recovery process along. Next time you’re really sore, spend an extra 10 to 12 minutes on this the following day. We guarantee it’ll help.

Time Your Nutrition

One addition you can make to your program is taking in some simple sugars and high-quality protein around your workout. This concept is called nutrient timing, and it’s supported by a good deal of research for supporting recovery and reducing muscle damage. See our detailed breakdown in Nutrient Intake Around a Workout: Part II for how to put it into practice.

Build Up Gradually

Because soreness tracks novelty, the single best way to avoid being wrecked is to progress sensibly. Jumping from nothing to a two-hour leg day, or adding a huge amount of weight overnight, guarantees a rough 72 hours. Increase your training volume and intensity in manageable steps and your muscles adapt with far less drama.

Don’t Reach for NSAIDs

Non-steroidal anti-inflammatory drugs like Motrin or Aleve have long been used to treat DOMS. Current research doesn’t support their use for it: results across studies are mixed and inconsistent in terms of type, dose, and timing, which makes any recommendation shaky. More importantly, since a certain amount of inflammation inside the muscle is part of how it adapts and grows, routinely blunting that inflammation with NSAIDs could work against the very adaptations you’re training for. Save them for when a medical provider recommends them, not as a standing post-workout habit.

When Soreness Is a Red Flag

The vast majority of post-workout soreness is harmless and fades on its own. Rarely, though, extreme muscle breakdown can lead to a serious condition called rhabdomyolysis, where damaged muscle releases its contents into the bloodstream and can overwhelm the kidneys. This is uncommon, but it’s worth knowing the warning signs, especially after an unusually intense session or a hard return from time off.

Stop and contact a medical provider promptly if you notice any of the following:

None of this is meant to scare you off hard training. It’s meant to help you tell ordinary soreness apart from the rare case that needs attention. When in doubt, get checked out. If you’re experiencing debilitating soreness on a regular basis, talk to your fitness practitioner so they can appropriately adjust your exercise program before it becomes a problem.

The Bottom Line

How sore you get and how good your workout was are not the same thing. Soreness is a rough signal of novelty and eccentric load, filtered through your own personal sensitivity. It is not a grade on your effort, a measure of muscle growth, or a goal to chase. A little is fine, a lot can set you back, and none at all is often a sign your training is right where it should be. Use the quick check below to see whether your soreness is working for you or against you.

About the Author

Michael E. Stack, BS, ACSM-EP, ACSM-EIM, ACSM-PAPHS, FMFA

Founder & CEO, Applied Fitness Solutions & Frontline Fitness Pros

Michael Stack is the founder and CEO of Applied Fitness Solutions, the Michigan Moves Coalition, and the President of the Physical Activity Alliance. He is an exercise physiologist by training and a health entrepreneur, educator, and policy advocate by trade, dedicated to making exercise professionals an essential part of healthcare delivery.

With a career spanning over three decades in fitness, health, and wellness, Michael holds credentials through the American College of Sports Medicine as an Exercise Physiologist (ACSM-EP), Exercise is Medicine practitioner (ACSM-EIM), and Physical Activity in Public Health Specialist (ACSM-PAPHS). He is a Fellow of the Medical Fitness Association and lectures nationally for ACSM, ACLM, and the MFA.