Muscle fatigue vs muscle soreness vs muscle strain | what’s the difference?

Discomfort is an integral part of strength training. In order to increase muscular strength, power or endurance, you need to move beyond the comfortable. (I’ve been known to tell my class participants “discomfort is where the magic happens”)

Sometimes discomfort is temporary. For example, when you’re completing the final repetition of an exercise set.

Sometimes it doesn’t make an appearance until the day after a strength training session. Not causing pain, but remaining with you for another day or two.

Sometimes it begins during or immediately after your workout and continues for days, weeks or even months.

muscle strain

Knowing the difference between mild temporary discomfort, moderate intensity longer term discomfort and immediate, long lasting muscular pain is important as if affects how you respond to the discomfort and whether you require medical attention.

1. Muscular discomfort that occurs towards the end of an exercise set is referred to as muscle fatigue.

Muscle fatigue is the consequence of a variety of physiological changes within the working muscle, including lactic acid build up (“feel the burn”), increased tissue acidity, nerve impulse interference and chemical energy depletion (“hitting the wall”). It is typically mild, temporary in duration and the discomfort passes once you cease performing the exercise.

Rx? Take a break, perform a different exercise and stretch it out before beginning your next set. No other attention required.

2. Muscular discomfort that doesn’t manifest until 24 to 48 hours following a strength training session is called Delayed Onset Muscle Soreness (DOMS). DOMS is typically associated with eccentric muscle contractions (the non-working phase of a lift) and is most likely the result of microscopic tears in the muscle or connective tissue. It can range from mild (just a bit of stiffness) to severe (sitting on the toilet is painful) and may take a day or two to diminish. (Personally, I enjoy feeling a bit of mild DOMS; it reminds me that I worked hard in the gym and have pushed myself well outside my comfort zone!)

Rx? Depending on the severity of the discomfort, you may need to take a day or two away from strength training the affected muscle group. Suggestions for alleviating the discomfort include warm baths, stretching, range of motion body weight movements and acetaminophen. No need to see a doctor of physiotherapist required.

Note that DOMS is NOT a sign of overtraining, just over-doing it on a particular set of exercises on a particular day.

3. Intense muscular discomfort that begins during or immediately after your workout and continues for several days or weeks is most likely due to a muscular strain. Strains are classified as mild, moderate or, in the case of a tear or complete rupture, severe. Strains can occur within the body of the muscle or in the tendon (the area of the muscle that attaches directly to the bone).

Rx? Regardless of severity, all muscular strains should be seen by a health care professional. The sooner the better. Although strains heal on their own, the scar tissue that results from the body laying down new collagen tissue is often weak and tight, thereby limiting your range of motion at the joint unless treated by a physiotherapist or chiropractor. Note that strains of the tendon typically take much longer to heal than comparably severe strains of the muscle itself (I can attest to this personally; it’s now been 7 weeks since I strained my Achilles tendon and despite daily stretch and strength therapy, I’m still not 100% 🙁 ).

Interested in learning more about DOMS and how to treat it? Check out the end of this post by A Doctor In the House (she’s included some scientific references to support the ideas; I love it when bloggers do that!)

Have you ever experienced DOMS or a muscular strain?

Do you enjoy a bit of discomfort in your muscles about a strength training session?




  1. for me it is all NO PAIN—GOOD THANG (I know. I too am so sad it doesnt rhyme. no pain no thain?) as since Im over 40 Im just happy to be able to still lift and if anything I UNDER PUSH.
    Miz recently posted…What’s your brand saying?My Profile

  2. This is such an important distinction. I’ve learned the difference myself the hard way and through trial and error, but it can be hard to communicate it to clients. Great info!
    Laura @ Mommy Run Fast recently posted…Summer Streets- A run and family day in NYCMy Profile

    • Laura, I agree! I try and have the discomfort vs pain talk with all of my new clients. I like them to know what it means when they’re a bit stiff the day or two after a workout and that it doesn’t mean they need to take the rest of the week off 🙂

  3. Excellent, excellent article! I love my DOMS, it’s an inventory of what I’m made of My cursory knowledge of it is that DOMS is actually the result of histamines being released to help repair the micro tears from the eccentric phase. Those histamines are very acidic and when they touch the nerve filaments of the motor units, it’s that acidity the creates the soreness. Oh college days — they still linger 🙂
    Contemplative Fitness recently posted…Minimal-list…My Profile

    • Thanks Roy. You know, in all of my reading, I have never heard the histamine part of the argument? And it surprises me that with all we know about the body, every article you read about DOMS cautions that we don’t know exactly what causes, but that ‘most people agree..’.

      Thanks for the info!

  4. Great post!!!
    I love that feeling of discomfort from really pushing myself.
    Sometimes when I have DOMS, I give myself an extra day to recover because I’ve learned the hard way that pushing through (for me) isn’t always a wise choice.
    Kim recently posted…Happy Birthday, Chris!!!My Profile

    • Yes, sometimes that extra day is necessary. Particularly when you can’t reach up to brush your hair or get up off the toilet without help. That’s always a sign to me to dial it back next time I’m in the gym!

  5. I love feeling sore. It feels good to know I pushed myself. However, I have learned my lesson after injuring myself on the silly Insanity DVDs (Achilles and ankle), don’t push through pain while working out..listen to your body. And this 40 something old body has no business jumping around that much LOL.
    Stephanie Robbins recently posted…It’s A New Year for this WAHMMy Profile

    • I hear you. A little bit of controlled jumping is fine. Insanity is just that (at least for some of us!)

  6. I have had the DOMS. I get it about once a year when training calves. But that’s about all.

    I have muscle strains, too. And LOVE, LOVE, LOVE K-tape for healing!

    unfortunately, my typical pain is a tendonitis from over use….
    deb roby recently posted…Start Where You Are. Do What You Can.My Profile

    • Tendonitis really sucks. And that’s definitely pain, rather than discomfort (I know; I’ve been dealing with it too). Did you have someone show you how to apply the K-tape yourself? I’ve just had my physiotherapist do it, but would like to be able to do it on my own.

  7. GREAT POST!!!!!!!!!!!!!!!!!!!!! Many do not know how to differentiate this! I LOVE MY DOMS – LOVE!!! 🙂 But over time & all my years working out, I have learned to know what is that & what is NOT a good pain.

    Thx for sharing all your knowledge!!!! YOU ROCK!!!!!!! I want to be like you when I grow up! 😉
    Jody – Fit at 55 recently posted…Gratitude Monday, Family, Bread & More!My Profile

  8. This is awesome! Definitely sharing.
    Kerri O recently posted…Paleo Breakfast Options – It’s Really Not All About The BaconMy Profile

  9. Tamara, as someone who has experienced all three conditions – and sometimes made dumb-ass decisions because I didn’t know how to respond to them – I appreciate this informative post. Lately my trainer and I have switched to heavier weights with less reps, so I’ve become well acquainted with muscle fatigue, but can tell it’s nothing more than that!
    Shira recently posted…Scaling back on self-judgmentMy Profile

    • Shira, we have all done that. Worked through pain thinking it was a good thing. Sounds like you have a great trainer; heavier weights and shorter sets can be super beneficial, not to mention efficient!

  10. I was suffering from a stress fracture for about 3 weeks, and my foot was so very bloated and puffy from it! You would think that I stopped working out because of it, but no, I am crazy and I continued and PRETENDED the pain wasn’t there. You know what’s weird though? It heeled!!!!! I did get a pedicure with an extra long foot massage and then another massage a few days ago, and my foot is SO MUCH BETTER if not completely heeled!!!!! Thank goodness. I appreciate my legs and feet so much, I don’t need them to be hurt/broken!
    GiGi Eats Celebrities recently posted…Do You Need A Rocket Scientist To Lose Weight?My Profile

    • Gigi, you always amaze me with your ability to push through. You must be younger (and heal faster!) then I…

  11. Great post! Very informative and to the point. I love feeling a little DOMS the next couple days. Am I crazy that I even sometimes like not being able to sit down on the toilet?? Yes, that’s crazy, I know..
    Heather Murphy recently posted…See- through pants and a baby liftingMy Profile

  12. Good distinctions to keep in mind. And then there’s another kind of pain that you don’t mention, the pain from overuse injuries that just kind of creeps up on you. All too easy for those of us who train regularly to confuse that with the normal DOMS from training.
    Mary @ Fit and Fed recently posted…Almond Flour Fig CakeMy Profile

    • You’re right Mary! And I am personally very familiar with that type of pain (although I’ve learned from my experience and don’t overtrain any more). Thanks for commenting and sharing that information!

  13. Thanks so much for the shout out!!! Love your post! 🙂 I sickly love feeling sore because it makes me think my workout was worthwhile… but then I hate being sore for the next 2 days!!

    • Andrea, thanks so much for stopping by and commenting. I like a little sore, but not so much that walking up and down the stairs hurt 😉

  14. totally! muscle strengthening will definitely discomfort you. one has to feel it if one wants to feel the changes in body.
    Pay heed to these 7 mysterious body aches and pains

  15. Hola! I’ve been following your website for a long time now and finally got the bravery to go ahead and
    give you a shout out from Kingwood Texas! Just wanted to tell you keep up the excellent job!
    Muscle X Max Review recently posted…Muscle X Max ReviewMy Profile

  16. Calf sleeves work great for this type of injury also!

    • Thanks for the suggestion. And I bet they look a whole lot better than tape too 😉

  17. Love my DOMS after a good hour in the gym lifting heavier weights than usual (off season)- the sorest I have ever been was after my Ironman events and I have fatigued my uphill muscles so much climbing (running) up Bright Angel out of the Grand Canyon after a double crossing, my calf muscles were involuntarily twitching! It didn’t hurt….and was crazy to watch!
    cherylann recently posted…Do you? Would you?My Profile

    • LOL! I have had an on and off crazy medial deltoid twinge for the past three weeks. I’m guessing it’s because I’ve changed up my shoulder workouts and they’re working! Love hearing about your events and event training Cheryl. Thanks for sharing!

  18. Hi, Tamara, this is a great overview of muscle soreness versus muscle fatigue, and strain. I like the feeling of muscle fatigue after a good workout too, and I sure don’t mind some DOM’s now and again.

    I think I can add a few points that could help. I hope you don’t mind.

    DOMS can sometimes show up almost immediately, although it is unusual…meaning within several hours the same day after the workout, although it is usually on the third day for most people. As we all know, there are no rules. I’d like to point out that DOMS is a part of even the most well-managed training and can result from anything ‘novel’ such as just trying a new exercise, so I wouldn’t want anyone to think that it was always the result of overdoing it on an exercise or two.

    Since the pain from a muscle strain might manifest right after a workout (it is possible that it won’t hurt at first, though), one thing to keep in mind is that the pain from a muscle strain is going to be more localized (although not always pinpoint) and the area of the strain will be very tender to touch or pressing, right over the strain, whereas DOMs will be more diffuse and not have point tenderness.

    Thanks for the great article!

    • Thanks so much for stopping by and sharing your thoughts Troy. Always happy to have other fitness professionals chime in and share their knowledge!

  19. I’m 59 and trying to strengthen my arms, and it seems I am not accomplishing that because I can do 20 reps of pushups (the girl type) and even after a few weeks, it’s a struggle to get through the 20. I feel like I should be gaining strength so that they become easier. Any tips or ideas? I’m taking BCAA’s and drinking a raw egg smoothie every day almost.


    • Hi Cheryl,

      You’re right. They should be getting easier with practice and should be able to increase the challenge of the move by coming up to toes for at least a few.
      Are you doing any other supplemental lifts for your chest? Bench press? Chest fly? Incline variations of the two?

      If you’ve plateaued, that means it’s time to switch it up. Try varying your exercises, reps and sets and see if that helps!

      Thanks for reading and commenting. Tamara


  1. […] check out Tarmaras overview of muscle fatigue versus soreness and pain. I won't to re-iterate some of the things I commented and add a few […]