Understanding post-exercise soreness

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Know the facts re exercise soreness

Are you crying tears of pain for your gains? Take a moment to understand the cause behind post-exercise soreness and how you can identify it and avoid it. Before earning my certification through the American College of Sports Medicine, I would have measured the quality of my workout based on exercise soreness the following day. It was something I had picked up from various fitness enthusiasts.

Had I been a little wiser on taking advice from non-qualified persons, I would have questioned this theory. However, I took a lot of information as fact and didn’t look for credible sources to confirm the things I had heard. The amount of false information that is passed around the fitness realm is kind of crazy. You may get the occasional gym veteran who swears on a particular theory that they’ve done for years; while their experience might be proof, I still prefer to rely on my good ‘ole ACSM textbook for solid facts.

I live for leg day!

I wanted to touch on post-exercise soreness and how to not only understand it but also identify the difference between what’s “normal” and what could potentially be a sign of over-training. I used to have a bad habit of over-training my legs. Yes, I am that weirdo that thoroughly enjoys leg day! I’d go hard on my legs and glutes and would find satisfaction in the extreme soreness the following day. If I could walk up the steps without wanting to cry, I didn’t work hard enough. A lady in our old neighborhood, who claimed to be a running coach, even encouraged my intense exercise because she agreed that it meant I was working my muscles properly. Again, had I been wiser, I would not have taken advice from someone who probably hadn’t run a day in her life.

Delayed onset muscle soreness

So, first of all, what exactly causes you to be sore after an intense exercise? Despite what your fellow gym junkies claim, it’s NOT lactate or lactic acid! “Unlike popular belief, lactate accumulation does not cause exercise soreness after intense exercise.” Battista, A. Rebecca, Ph.D., FACSM, 2018, page 146. Although they are very similar, lactate and lactic acid are not the same, and are commonly interchanged by trainers, and have been the victim of false accusations for a while. In reality, lactate acid is protecting your body when your muscles become acidic from high levels of intense exercise. If lactate is found innocent, who is the real culprit responsible for your need to brace yourself against the walls in order to sit down on your porcelain throne?

It’s called delayed onset muscle soreness, or better known as DOMS. DOMS happens after intense exercise and can last for several days. The intensity of the workout depends on the person. An intense training session for one person could be easy for another person. The soreness you experience with DOMS can be mostly due to micro-trauma. Mechanical stress (e.i. lifting weights) causes microscopic tears in your muscle fibers. You muscle fibers then send out an S.O.S. to satellite cells to add new muscle proteins. The result is mild soreness and a slight increase in muscle size.

Potential hazards of over-training

It’s essential to understand the difference between what is “normal” and what is over-training. Ideally, you shouldn’t have to brace the bathroom walls when you go to the loo. Mild soreness shouldn’t interfere with your daily living. If you’re experiencing chronic discomfort or pain, you could be over-training. Over-training can also lead to not progressing in your training regimen. Your gains from working out are created during your rest period when your muscles are recovering. That recovery period is so crucial. Other side effects of over-training can include but aren’t limited to lack of appetite, sickness, chronic fatigue, and lack of program adherence, to name a few.

Pay attention to exercise soreness

How can you avoid potentially over-training? It is important to mind your body! If you’re unfamiliar with exercise programming, I would highly suggest seeking out a personal trainer. If hiring a trainer isn’t in your budget, you could always ask a trainer to review your program to ensure you’re not over-training. If the trainer isn’t totally whack, they shouldn’t mind taking a peek for you. Another way to avoid over-training is to listen to your body! If you go too hard on your hammies, they’ll be screaming at you the next day. It’s okay to experiment with your program and get a feel for where you are in your abilities. Last but certainly not least, let your muscles rest. They need to recover just as much as you do after a long day of work. Happy lifting!


While I am a personal trainer, I am not a doctor.  The information provided in this article is not intended to substitute for medical advice from your provider. Any recommendations within this post are not intended to diagnose, treat, cure, or prevent any disease. You should consult with your physician before beginning any exercise program.

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