Why Do Your Muscles Feel Sore After You Workout?

Delayed onset muscle soreness (DOMS) is the technical term for the pain and discomfort some people experience following an intense workout.  DOMS is categorized as a subclinical muscle strain injury and those experiencing it may have to contend with soreness and stiffness in the affected area(s) for up to 72 hours post-workout. (1)

While the sensation itself can last for days, the level of soreness each person feels can vary significantly.   Some people may only experience minor soreness, which doesn’t really hinder their daily lives, while others may feel far more debilitated.  In some of the more severe cases, even basics every-day movements can become incredibly painful. (2)

So what actually causes DOMS and is there anything you can do to treat or even prevent it?  

What Causes Delayed Onset Muscle Soreness?

Over the years, researchers have come up with a number of theories in attempts to explain what causes delayed onset muscle soreness.  Muscle spasms, inflammation, as well as muscle and connective tissue damage have all been cited as potential causes of DOMS. (3)

While numerous studies have examined each of the potential causes mentioned above, researchers have come to a general agreement that delayed onset muscle soreness is likely caused by a combination of different factors rather than one single thing.  

The general consensus is that DOMS occurs as a result of a multi-step process.  The first piece of the equation is muscle and tissue damage, which can happen during intensive exercise.  

Eccentric movements in particular — think lowering the bar to your chest on the bench press — can place an incredible amount of stress on your muscle fibers and connective tissue, which in turn can cause damage at the cellular level. (4)

The stress and consequent damage to the muscle and connective tissues triggers an influx of histamine and other nitrogenous fluids into the affected areas.  The over-accumulation of these fluids causes inflammation which can ultimately translate into muscle pain and immobility.(5)

It’s important to point out that lactic acid does not appear to be one of the forces at play when it comes to delayed onset muscle soreness.  Lactic acid build-up was once theorized as a potential cause of DOMS but most researchers now believe it’s not a contributing factor.

The main reason lactic acid is not believed to be a factor when it comes to DOMS is that even when lactic acid build does occur, levels usually return to normal within an hour after you’re finished exercising.  Such a quick return to normal doesn’t really help to explain the existence of pain and discomfort 24, 48 or even 72 hours after a workout.(6)

Who’s Most Likely to Gets DOMS?

Delayed onset muscle soreness is most commonly experienced by people who are new to working out or who have been away from the gym for an extended period of time.  DOMS are most likely to happen when your muscles are not used to the types of physical activity they’re being tasked with.(7)

So for example, if you’re just getting back into the gym and it’s your first couple of weeks doing squats, you’re far more likely to get DOMS, compared to someone who has been doing the same basic squat routine for the past year.     

Even if you’ve been strength training for a while, you’re still more likely to experience DOMS when you switch up your routine. Again it all comes down to your body and your muscles getting used to the types of exercises that you’re performing.  

DOMS aren’t just caused by introducing new exercises into your workout program either.  They can also be caused by working at higher intensity levels on exercises you’re already used to.  Increasing things like the amount of weight you’re lifting or the number of sets and reps you perform can also increase your likelihood of experiencing muscle soreness afterward.  

Can Athletes Get DOMS?

There’s a pretty common myth out there that athletes don’t usually have issues with delayed onset muscle soreness but the fact of the matter is that they actually deal with DOMS on a somewhat regular basis.

 DOMS are particularly common in athletes who are just coming back to a sport from the offseason, where they may not have been training as regularly.(8)

Even if you’re in game-ready shape, DOMS are also commonly experienced by athletes experimenting with new or altered training methodologies.  For instance, let’s say you’re a hockey player who spends most their training time on the ice, but maybe you decide some off-ice agility training may ultimately help you perform better come game time.  

While that may certainly be true, introducing your body to new stimuli that it’s not used to increases your likelihood of experiencing muscle soreness afterward.

 Now we’re not saying you shouldn’t add new or alternative approaches into your training every once in a while, but rather that you should know how those changes are going to affect your recovery so that you can plan accordingly.   

Should You Keep Exercising if You Have DOMS?

You certainly don’t want to force yourself when it comes to training; however, there’s nothing wrong with working through a little soreness at the beginning of your workout.  For those only experiencing minor DOMS symptoms, most of the soreness will likely subside after you’re warmed up.

For those with more severe symptoms, you will want to be mindful of your limitations when you’re exercising with some soreness.  In addition to affecting your range of motion, DOMS can also reduce your strength and overall power output, which means that you may need to step back the intensity if you’re lifting while you’re muscles are sore.(9) 

While it might be tempting to go through with your normal routine, changing things up to accommodate your sore areas can help reduce your risk of experiencing more serious injuries.  That means potentially lightening the loads on some lifts or avoiding certain exercises all together if they’re too aggravating.

How to Treat Delayed Onset Muscle Soreness

A number of studies have investigated preventative strategies for DOMS; however, to date, scientists have yet to identify a clear and reliable practice for preventing delayed onset muscle soreness.  With that being said, researchers have explored a number of potentially effective treatments.

Massage Therapy

Numerous studies have found massage therapy to be an effective treatment for DOMS. (10)  For example, one study investigated the effects of massage therapy on female collegiate basketball and volleyball players experiencing DOMS. (11)

The researchers compared a control group to another group of athletes who received regular post-exercise massages and found that those receiving massages also reported significantly less soreness later on.

 The researchers also found that the massage group, on average, were able to perform better on a vertical jump assessment.

Foam Rolling

Similar to post-workout massage therapy is foam rolling.  You can think of a foam roller kind of like a dough pin, where you apply the roller to the affected area(s) kind of like you would the pin to piece of dough.  Some research suggests that foam rolling may also be an effective treatment for delayed onset muscle soreness.

One study found that post-workout foam rolling significantly decreased the severity of quadricep-related soreness felt in the days following an intense leg workout.  Study participants who foam rolled post-exercise also on average performed better across a number of strength and endurance-based performance measurements. (12)

Supplementation

Another treatment for delayed onset muscle soreness is supplementation.  More particularly, supplements associated with leucine metabolism may also aid in preventing some of the subsequent fluid build-up that occurs following intensive exercise.

Several studies on BCAA supplementation, for example, have found that taking them before and/or after high-intensity exercise helps to both reduce muscle damage and speed up the recovery process.(13) 

There is also some evidence that other leucine metabolites like HMB and HICA may also work in similar ways to attenuate exercise-induced muscle damage. (14)(15)(16) However, there haven’t yet been enough studies to say anything for sure.

Analgesic/Anti-Inflammatory Medication

Researchers have also investigated the effects of analgesic and anti-inflammatory medication on delayed onset muscle soreness.  

Up until this point, the findings have been mixed; some research has demonstrated positive results, while other studies failed to demonstrate any effects at all.  

On top of the mixed findings when it comes to treating DOMS, some research also found that analgesic medications like Advil and Tylenol may interfere with your body’s ability to react and adapt to your training. (17)

Long story short, there appears to be limited evidence that analgesic drugs may help to alleviate some of the symptoms associated with DOMS.  However, the trade-off is that taking certain pain medications as a treatment for muscle soreness may impinge on your ability to build size and strength.  

What About Ice?

One of the most commonly recommended treatments for DOMS is ice; however, numerous studies have found cryotherapy to be ineffective when it comes to treating delayed onset muscle soreness. (18)(19)

For instance, one study had participants do eccentric arm exercises with both arms, after which they submerged only one arm in ice water for 20 minutes, five sperate times over the course of the day.  

The researchers ultimately found no difference in soreness between the test arm and the control arm.  Furthermore, the arm that received ice performed no better than the control arm across a variety of different power-related assessments when participants returned to training. (18)

Wrap Up

Delayed onset muscle soreness is a condition that affects everyone from top-level athletes to first-time gym-goers.  It’s most commonly experienced by people whose bodies are not used to the type of activities they’re being tasked with.  

For athletes, that can be a scenario like coming back to full-time training after the offseason.  For casual gym-goers, DOMS are most likely to occur when you’re doing new exercises that your muscles aren’t familiar with.    

While a reliable preventative measure has yet to be fully fleshed out, there do appear to be a few effective treatments for delayed onset muscle soreness.  Post-workout massage therapy and foam rolling, in particular, appear to be amongst the most effective. Supplementation may also help to reduce some DOMS symptoms.  Cryotherapy, on the other hand, doesn’t appear to be all that effective when it comes to attenuating exercise-induced soreness.