Sore after a workout? Understanding DOMS and what it means for your training

You want to get stronger. You still need to function tomorrow

Work, family, stairs. Getting out of the car without making sound effects. There are practical reasons you might be reluctant to book a workout that could leave you sore for days.

If that has happened before, being told to “just get started” probably doesn’t answer your actual question: will this be something I can manage and keep coming back to?

You don’t need to be sore for training to be worthwhile. But that doesn’t mean soreness is meaningless or something we should ignore. We can use it as feedback without treating it as a score.

What Is Next-Day Soreness?

Delayed onset muscle soreness, or DOMS, is the tenderness and stiffness that can develop after exercise. It typically begins around 12–24 hours later and is often strongest between 24 and 72 hours afterwards. That delay distinguishes it from discomfort that starts during an exercise. [1]

It’s more likely after unfamiliar activity or an increase in what you’re doing. Exercises that load a muscle while it lengthens, called eccentric actions, are particularly associated with it. Think of lowering the dumbbell in a bicep curl, rather than lifting it. Familiar exercise can cause soreness too; novelty isn’t the only factor. [1,2]

Microscopic Muscle Tears—or Lactic Acid?

You might have heard that soreness comes from “microscopic muscle tears.” Small-scale damage to muscle and surrounding tissues can happen after exercise, particularly when the work is unfamiliar. But that explanation doesn’t tell the whole story. [1,2]

Exercise can also trigger chemical messengers that make nerve endings in those tissues more sensitive. That means pressure and movement can feel more uncomfortable afterwards, like when sitting down to go to the loo suddenly makes you very aware of yesterday’s squats. [2]

Researchers are still investigating how these processes fit together. What we do know is that how sore you feel doesn’t reliably tell us how much tissue damage there is. [2,3]

What About Lactic Acid?

That’s a familiar explanation, but research doesn’t support it as the cause of delayed soreness. Your body produces and uses lactate during normal metabolism and exercise, including as fuel. It isn’t leftover waste sitting in your muscles and making you hurt days later. [9,10]

There’s another part of the “tiny tears” story worth questioning: the idea that more damage means more growth.

Repairing damaged tissue and building additional muscle aren’t the same thing. You can gain strength and muscle without chasing soreness or deliberately trying to cause damage. [4,6]

So we have useful explanations for parts of the process, without having every detail settled. None of that makes soreness a useful score for how beneficial your workout was.

Why Does the Same Session Leave You Less Sore Later?

After exposure to similar exercise, your body often responds with less soreness. This is part of what researchers call the repeated bout effect. It isn’t a promise that soreness will disappear after a certain number of sessions, but it helps explain why a familiar workout can feel different from your first one. [5]

Less soreness alone doesn’t tell us whether the program needs changing. We’d look at your goals, how challenging the work is and what’s happening over time. Are you managing more repetitions at a similar effort? Using more resistance with comparable control? Finding a daily task easier?

That’s much more useful than trying to recreate the aftermath of week one.

What Should You Do When You’re Sore?

If your muscles are a little tender the next day, you don’t need to panic or prove anything by pushing through another hard session. A gentle walk or some easy movement might feel nice. Keep it comfortable, and give yourself permission to do less if that’s what you need. Feeling better once you get moving doesn’t necessarily mean you’re fully recovered. [1]

And please tell me how you’re going. You’re not complaining or weak for letting me know. “My thighs feel a bit tender, but I’m getting around fine” tells me something different from “the stairs are a struggle and I’m worried about coming back.”

We can work with that. Maybe we change the weight, do a little less, choose different movements or give those muscles more time before another challenging session. You don’t have to arrive knowing which adjustment you need, that’s something we can work out together.

What If You’re Repeatedly Sore for Days?

One unfamiliar session leaving you tender is different from a pattern where you’re struggling between almost every workout.

We’d look at the training itself: how much you’re doing, how quickly it has increased and how sessions are spaced. We’d also talk about what’s happening between them.

Sleep, enough food and replacing lost fluids all help support recovery. Protein provides building blocks for repair and adaptation, while carbohydrates help replenish the fuel used during exercise. That doesn’t mean a protein shake will magically switch off soreness, or that feeling sore means you’ve eaten badly. [11–13]

And if sleep is currently a negotiation with your hormones, your children or your own brain, “just get more sleep and recover better” isn’t particularly useful advice. We can work with the circumstances and the capacity you have and adjust the training accordingly.

You don’t need a perfect recovery routine. But you also don’t need to keep repeating a session that leaves you struggling and hope you’ll eventually get used to it.

If soreness keeps disrupting your days, tell me. We can review the plan. If symptoms persist, worsen or don’t seem like your usual muscle soreness, we shouldn’t assume that more rest or different food is the whole answer.

When Should You Get Checked?

Most ordinary post-workout soreness settles with time. If yours is getting worse, isn’t starting to ease over several days or just doesn’t feel right, check in with a qualified health professional.

There’s also an uncommon condition called rhabdomyolysis, involving substantial muscle breakdown. Exercise-related cases can follow unusually strenuous or unfamiliar effort; heat, illness and some medicines can also play a part. It isn’t an expected part of a gradually progressed exercise program. At Fearless Movement, we build the challenge with you rather than aim for exhaustion. [7,14]

Unusually severe muscle pain, marked swelling or weakness, or dark/cola-coloured urine after exercise needs urgent medical care. You don’t need to have all of these together or wait for a reply from me. [7,8]

Training With a Purpose You Can Recognise

At Fearless Movement, we choose a challenge that makes sense for you and build from there. That can include working hard. It also includes changing the plan when the response tells us we need to.

I can’t promise you’ll never be sore. What I can do is listen, pay attention to how you recover and use that information to guide the next session.

The aim is to build strength and capacity over time, with room for the rest of your life. You don’t need to spend days struggling to sit down on the loo to prove you’re committed.

Coming Next: What Actually Helps You Recover?

We’ve talked about what soreness can and can’t tell you. Next, we’ll look at what happens between sessions: food, sleep, training schedules and the adjustments that can help when life is already asking quite a lot of you.

Practical recovery support, without turning it into another full-time job.

If you’re thinking, “I’d like to start, but I’m worried it’ll be too much,” tell me that bit. Message me and we can talk about a manageable starting point.