Is it normal to feel sore after you start exercising?
Yes. Achy, stiff muscles that turn up a day or two after a new or harder activity are very common, have a name (delayed onset muscle soreness, or DOMS) and usually fade within a few days. Sharp pain, swelling, pain that lasts more than about a week, or dark urine are different, and those are reasons to stop and get checked by a doctor.
Zestasy Wiki: our reference answers. Checked for facts and sources; less curated than the magazine.
You go to your first class, or play five-a-side for the first time in years, and feel fine. The next morning, also fine. Then on day two the stairs become a negotiation. This is so common it has its own acronym, and it is not a sign you did anything wrong.
What it is, in plain words
The Cleveland Clinic's page on delayed onset muscle soreness describes DOMS as muscle pain that follows exercise your muscles are not used to, usually starting one to three days afterwards and fading within a few days. It is most likely after a new activity or a session harder than usual.
The "delayed" part is what confuses people. The Wikipedia summary of DOMS notes that the soreness is usually felt most strongly 24 to 72 hours after exercise. It also notes that the old explanation, a build-up of lactic acid, is largely discredited.
Why some activities do it more than others
Both sources point to the same culprit: movements where a muscle is working while it lengthens, like lowering into a lunge, landing from a jump, or running downhill. That is why a hilly walk can leave your thighs complaining more than the climb itself suggested, and why the walk down a mountain is the part people remember on Tuesday.
The other common trigger is simple novelty. A sport you have never played asks your muscles to do things in an unfamiliar order. The good news, according to the Wikipedia summary, is that muscles adapt quickly: repeat the same kind of activity and the soreness usually gets much milder.
What to do about it
Nothing dramatic. The Cleveland Clinic notes that rest is generally the main approach, and that gentle movement is fine. In practice:
- Move gently. An easy walk or a relaxed bike ride often makes stiff legs feel more willing. Our piece on active recovery is about exactly this kind of easy day.
- Do not chase it. Soreness is not a score. A session that leaves you barely able to sit down is not a better session.
- Build gradually. The second and third time you do something, keep it a little shorter or easier than you feel like doing. It is far more fun to come back on Thursday than to spend the week recovering from Monday.
- Expect it with anything new. Trying climbing, skiing or a dance class? Your body will notice. That is a sign of something new, not of being unfit.
When soreness is a sign to back off
DOMS is a dull, general ache in the muscles you used, worse when you move or press them, getting better day by day. Other kinds of pain deserve more respect. The Cleveland Clinic lists reasons to see a healthcare provider, including pain lasting more than a week, sharp and constant pain, severe swelling, or dark or bloody urine, and says severe pain or being unable to move a body part also warrants a visit.
Our everyday rule of thumb on top of that: pain in a joint rather than a muscle, pain on one side only after a twist or a pop, or pain that is getting worse instead of better is not "normal soreness". Stop, rest it and ask a professional.
FAQ
Should I exercise while I am still sore?
Light, easy movement is usually fine and often feels good. Save the hard version of whatever made you sore until the ache has mostly gone.
Does stretching stop soreness?
Stretching can feel pleasant, and that is reason enough to do it. We would not count on it to stop next-day soreness, though; easing into new activities gradually is the more dependable approach.
If I am not sore, did the session work?
Yes. Soreness mostly reflects novelty. As you get used to an activity it usually fades, while the enjoyment and capability carry on growing.
Why am I sorer on the second day than the first?
That is the classic pattern. The ache tends to build for a day or two and then ease, which is exactly why it is called delayed.
Sources
Written by the Zestasy editors. General information for curious adults, not medical, nutrition or training advice.