Dangerous Post-Workout Soreness

While it's normal to feel some mild soreness in the day or two following a tough workout, ​extreme muscle soreness​ is an indication that something is wrong. If your post-workout soreness keeps you from continuing to work out or pursue everyday activities, it's a big, flashing signal that you need to either dial back your workout intensity, double-check your workout form, change some lifestyle factors that affect your exercise recovery or perhaps all of the above. In certain cases, you might even need immediate medical intervention.

First, a look at the "normal" ​delayed-onset muscle soreness​, also known as DOMS, that you might experience after trying a new workout or increasing the intensity on a familiar workout. This sore feeling ​in your muscles​ typically sets in within 12 to 24 hours of the workout and lingers for up to three to five days. Soreness that doesn't improve within this time period is a signal that something is off.

Although the mechanism behind DOMS isn't entirely understood, it's believed to be caused by microscopic tears in your muscle fibers. To a certain degree, this is a natural part of working out, and your body actually gets stronger during the post-workout rebuilding and recovery process — not during the workout itself.

But don't mistake DOMS for a badge of honor; although you can be justifiably proud of the effort that goes into a tough workout, you don't have to push yourself to the point of debilitating soreness to reap the benefits of strength training or other exercises.

​Read more:​ How to Ease Muscle Soreness After a Workout

If your ​DOMS symptoms​ get worse rather than better or if they're accompanied by dark urine or swelling and stiffness in your limbs, that's a signal that you might have the life-threatening condition rhabdomyolysis, sometimes abbreviated simply as "rhabdo." Rhabdomyolysis is characterized by the breakdown of muscle protein into your bloodstream, and severe cases can lead to kidney failure or even death — so if you exhibit these symptoms, you should seek medical attention immediately.

Rhabdomyolysis typically occurs after extreme exercise, which is why, for a time, it was publicized largely in connection with CrossFit workouts and sports teams, both of which are focused on pushing athletes to the extremes of their ability. But other factors, including physical trauma, working out in extreme heat and use of drugs, such as cocaine, heroin and amphetamines, can also cause it.

​Read more:​ The Controversy Behind CrossFit

What if your post-workout soreness doesn't feel like DOMS or rhabdomyolysis? If you experience sharp pain in a muscle or joint, or if your muscle pain doesn't go away when you stop your workout or reduce your intensity, ​you may have a strain or a sprain.​

The difference between the two depends on what's injured: A muscle strain is an injury to your muscles or the tendons that connect them to bone, while a joint sprain is an injury to the ligaments that connect and stabilize your bones at the joints.

In either case, you can usually treat mild cases at home with the classic "RICE" method (rest, ice, compression and elevation). However, the Mayo Clinic warns that if your symptoms worsen, if your pain is intolerable or if you experience numbness or tingling, you should see a doctor. Severe strains and sprains may require medical intervention, up to and including surgical treatment.

​Read more:​ What Are the Treatments for a Torn Muscle?

Even if your soreness hasn't gone quite to the point of rhabdomyolysis or an acute sprain or strain, ongoing ​extreme muscle soreness​ signals that something isn't quite right in your workout program. It's possible that you simply started out with too much, too soon.

One possible solution is dialing back either your workout intensity, your workout duration or your workout frequency — or scaling back all of these, and then gradually increase one variable at a time as your body adapts to the new demands you're placing on it. Taking the time to warm up before you work out and then cool down and stretch after can also reduce after-workout soreness.

You might also end up with ​severe DOMS​ symptoms if you don't give yourself enough recovery time between workouts. Light "recovery" workouts can actually help soothe soreness, but doing intense workouts before the soreness subsides can just make it worse.

You should always give yourself at least one full rest day between strength-training workouts for any given muscle group. But if your muscles continue to be sore after that day has passed, wait until the soreness subsides before you work them again. (The same guideline applies to non-strength-training workouts such as running.)

If dialing back your workout intensity doesn't get rid of your muscle soreness and you're not injured or have a medical condition that causes you muscle pain, there's another possible cause for your discomfort: ​poor workout form​. There are plenty of examples of improper workout form in gyms and even in the media, so to suss out your errors in form, you're going to have to be brutally honest.

If it's strength training that's leaving you sore, ask yourself if you're "heaving" the weights to get them in place, speeding up to keep the weights moving or losing control of the weights during your workout. If the answer to any of these questions is yes, reducing the amount of weight you're lifting might help your form.

In other cases — whether you're getting constantly sore from other exercises, such as running, or if you've reduced the amount of weight you're lifting and still find yourself in pain after working out — it's well worth the investment of time and money to consult with a professional who can help you spot and correct any errors in your technique. Not only will you be addressing the cause of that soreness, you'll also be heading off bad movement habits that might lead to injuries or muscular imbalances (which can, in turn, cause injury) later on.

If you're trying to figure out whether you should hit the gym again, let your body be your guide. ​Working out while you're mildly stiff or sore​ is generally OK. But if working out makes the pain worse or affects your exercise form, or if your muscles feel weak or something just "isn't right," stick to gentler "active recovery" exercises like walking, stretching and lifting light weights. Basically, anything that gets your body moving but doesn't stress it.

And remember: If your soreness worsens or is accompanied by symptoms such as limb swelling, dark urine or muscle weakness, these may signal a life-threatening condition. Contact a doctor immediately.

Since mild to moderate soreness is fairly common, what can you do to bounce back after a workout that might leave you sore? The answer is quite a lot. Aside from the guidance to warm up, cool down and stretch as part of every workout, and proactively monitoring your exercise intensity so you don't work yourself into debilitating soreness, a little strategic self-care can help you bounce back after a tough workout.

These guidelines, laid out by the Mayo Clinic, include rehydrating after your workouts, eating a post-workout meal or snack that includes both carbohydrates and protein to replenish your body's energy stores, keeping active so you don't fall into a "boom and bust" exercise cycle that leaves you constantly sore, and getting plenty of sleep.

Keep in mind that although sleep deprivation may be a fact of life with today's hustle-and-bustle lifestyles, ​getting enough shut-eye can make a big difference in how you recover​ after your workouts. According to a study published in a 2017 issue of the European Journal of Applied Physiology, a single night of partial sleep deprivation was enough to impair trained cyclists' recovery from a single session of high-intensity interval training, or HIIT, exercise.