Is It Okay to Work Out With Sore Muscles?

Ah, one of the age old fitness questions: Is it okay to work out on sore muscles? More isn’t always better when it comes muscle growth and strength, but where do you draw the line between some soreness, and actively taking a rest day?

This question is most frequently asked by beginners who are still learning their bodies, and what they’re capable of. The weathered lifter, or strength athlete, generally understands when to push through, and when to ease up due to severe DOMS.

Muscle Soreness 101

Delayed onset muscle soreness, or DOMS, is the term used to describe the soreness we feel after working out. Muscle soreness is somewhat complex and ranges from moderate discomfort to losing the ability to move efficiently. Soreness pain is an okay superficial indicator for assessing the damage you’ve placed on your muscles.

For example, if you can’t even sit on sore leg muscles, then chances are you’ve really pushed your body’s limits and caused some pretty heavy muscle damage.

Lactic Acid

There a few factors that make a muscle feel sore, and the first piece of the puzzle we’ll look at is lactic acid. Most know lactic acid as the byproduct of muscle metabolism that gives them “a pump” feeling. A lot of people associate lactic acid as a bad thing, but it’s actually completely normal.

[Foam rolling can be a great tool for aiding muscle soreness. Check out this guide on how to roll the hips for soreness and mobility.]

It becomes a burden when there’s an accumulation in the muscle and your body can’t keep up with clearing it. When you’re pumped and feel the limited range of motion, strength, and power decrease, that’s a good indicator that you’ve hit your lactic acid threshold. Essentially, the body can’t keep up with the production of this compound, so it begins to pool and irritate muscle. Lactic acid, a muscle irritant at times, isn’t the true cause for muscle damage.

Microscopic Damage, Swelling, and the DOMS Theory

Believe it or not, the exact reasoning for soreness pain caused by DOMS is still not totally understood. DOMS can last anywhere from 24 hours to multiple days depending on damage.

It’s pretty widely accepted that DOMS is a result of multiple tears along a muscle. Small tears in the myofibrils of muscles (muscle fibers) are what cause the main feeling of soreness, and that pain is a decent indicator of where growth is happening. As the muscles becomes stressed/damaged (aka sore), then we’ll produce compounds to repair them. Just like any wound to the body.

[Can’t sit still on rest days? Check out this guide on programming active recovery days.]

These microscopic tears in the connective tissue are most often caused by the eccentric portions of movements (muscle lengthening phases of exercises when muscles are under the highest amount of tension). The microtraumas or tears swell up with muscle healing components like white blood cells, calcium, and other compounds. When the muscle has multiple micro tears and swells, then it becomes increasingly more sensitive (through heightened neural sensors), hence why even light impacts can be painful on a sore muscle.

Should You Work Out On Sore Muscles?

Yes and no. There’s not a clean cut answer to this question, because everyone has different training goals and thresholds. Also, severe DOMS can actually be counterproductive to increasing strength and muscle (yes, there’s a point of diminishing returns).

This is why the above question gets so complicated; how does one find the happy medium of working out, and judging muscle soreness for growth?

Things we know about muscle soreness and DOMS.

  • Not always, but some muscle soreness can be an indicator of muscular hypertrophy. This is due to the body building and repairing on damaged muscle to make it stronger/bigger.
  • You don’t always need a muscle to be sore to grow.
  • DOMS intensity can range from multiple intensities. Typically the amount of heavy eccentric loading will dictate the length and intensity of DOMS.
  • Often times when an athlete performs a heavy session, a new form of workout, or intense workout after time off, then the time span of DOMS will be longer.
  • DOMS is thought to be a product of micro tears in connective tissues in the body.

Practical applications to use to assess if you’re sore, but workout ready.

There’s a fine line of diminishing returns with sore muscles. A goal every athlete should have is to accurately create programs for themselves that produce frequent progressive overload without excessive soreness, or decrease in performance.

If we understand DOMS and muscle soreness, then we can make educated decisions on how our bodies will react to various workouts, and when to workout. Taking it one step further, if we account for an athlete’s sport, threshold, and goal, we can really dial in the question.

Below are a few steps/questions you can use to help assess working out on sore muscles.

  • Step 1: Record what you do every workout. This way you’ll have baselines of understanding your workout’s intensity, which can help for future programming.
    • For example, maybe one day you need to ease up on heavy eccentric work if you find that you’re sore for multiple days after a workout. Can’t remember what you did? That can be a haphazard issue easily solved by recording your work.
  • Step 2: What’s your training goal? This will depend on your sport, and will help you decide on your workout.
    • For example, a powerlifter that’s sore will have a tough time recruiting maximal motor units and muscle fibers on heavy lifts, so lifting sore can be counterproductive. On the other hand, a functional fitness athlete can sometimes get by doing a workout with some soreness, as the body requires less neural drive in some lighter high volume bouts (this is a case by case, athlete by athlete scenario).
  • Step 3: How intense is your workout? This will be similar to the question above. But how heavy, or intense are you going?
    • For example, if you’re lifting at a 85%+, or an RPE 8+ intensity, then you may want to take a little extra time off. Damaging already sore muscles further by intense exercise can prolong the amount of time you have to take off. Not to mention, the neural stress you’ll be placing on the body.
  • Step 4: Program like a wizard and cycle intensity. This is why block periodization and undulated programs are so popular. They cycle intensity bouts from heavy, moderate, and light.
    • For example, if you frequently program every day to be extremely intense, then your body won’t have the time to recover. Volume and intensity (amount of weight lifted relative to your 1RM) are two of the bigger factors to consider when programming wisely.
  • Step 5: Be Honest. There’s no shame in taking an extra 12-24 hours off if it helps avoid excessive soreness, or missing lifts due to soreness.
    • For example, more often than not, I find that folks who are asking if they should take time off due to sore muscles, deep down know they should. Remember, rest is one of the biggest factors of growth – don’t sacrifice gains for mental impulse, or boredom.

In Conclusion

The above question is far from straight forward. It’s going to come down to an athlete and coach assessing multiple factors. A goal should always be to progress in the gym, and not take steps backwards. If you’re finding that excessive soreness is holding you back, then take a minute and assess where your programming may be going wrong.

Editor’s note: Steve Hamlin, Owner & Coach/Trainer at Endurance Path, had this to add after reading this article:

“When it comes to strength specific training, then I typically won’t do another hard workout on the same muscle groups if they are not truly recovered. Instead of another hard workout, I’ll replace it with some really light work with a larger focus on stability. I’m still getting a workout, increasing circulation of blood flow to those muscles and keeping loose, which I think helps aid in recovery, without overdoing it and stacking up damage.

I take the same approach when it comes to cycling workouts… I’ll throw in a 30 to 60 min easy recovery spin on days between heavy interval workouts to keep my legs loose, while recovering from the previous day’s heavy workout, such as hill repeats or max power intervals. I’ll even push out the next interval workout by a day and replace with the same easy recovery spin, if I’m not recovered enough from the previous workout to get the most out of the upcoming interval workout.”

Feature image from @lisahaefnerphoto Instagram page.