When Exercise is Too Much: CrossFit and Rhabdomyolysis

    Whether you’re a regular CrossFitter or brand new to an exercise regimen, there’s a little known condition you might want to be aware of. Even when I studied Exercise Physiology in graduate school, we didn’t learn about this syndrome nor was there ever a focus on the dangers of it. I’m talking about rhabdomyolysis, specifically of an exertional origin. Tiffany Beeson investigates the potential link between CrossFit and rhabdomyolysis.

    This condition is sometimes associated with CrossFit due to the nature of the training programme, which includes high intensity exercises, but it can happen with any type of muscle overexertion and there are other causes as well (such as crush injuries, certain infections and medications). If you’ve never heard of this particular condition, you’re not alone, but it’s important to recognise the symptoms in order to seek medical attention if needed.

    This potentially life-threatening syndrome results from the breakdown of skeletal muscle fibres with leakage of muscle contents into the body’s circulation system. When injured/overused muscle fibres die and release their contents into the bloodstream, the toxins can impair the kidneys and cause serious complications. Fortunately, with prompt diagnosis and treatment, a full recovery is expected. 

    Let me back up a little and say that under typical exercise conditions, tiny tears in your muscle naturally occur as you put your muscles under the stress of exercise. This often results in some soreness, especially if you’ve just started a new programme or have recently increased your intensity. It is through the process of repairing those micro-tears that you actually get stronger and build more muscle.

    Sometimes the soreness from a workout takes a day or two to manifest. You may have noticed feeling more sore the second or third day after a workout. This is called delayed onset muscle soreness, or DOMS, and it occurs over time as metabolic and physiological processes happen. If you build up your exercise activity gradually, DOMS is less of an issue. Normal muscle soreness goes away on its own in a couple days. With rhabdomyolysis, the soreness may be extreme and you may have muscle swelling as well as dark coloured urine or lack of urine. Unlike DOMS, rhabdomyolysis is a serious condition that requires medical attention. It can happen when someone jumps into heavy activity without building up to it.

    While rhabdomyolysis is not commonly considered, a mum I know here in Hong Kong was hospitalised with it a few months ago.  I spoke with her about the whole experience and here’s what she had to say.

    Woman doing CrossFit

    What Were You Doing That Lead to the Condition? 

    I was doing a “negative pull-ups” workout that was designed for 5 rounds of 3 reps with a 2 minute break between each round. This was a modified version of the pull-ups workout that others in the gym were doing, designed to focus on and build up the arm muscles to eventually be able to do a pull-up. The movement requires standing on a wooden box and grabbing the pull-up bar from a standing position. Then you step off the box and try to do a slow, controlled extension of the arms, holding yourself in a hanging position before coming all the way down.

    By about the 7th negative pull-up, I felt like I was just “dropping”. I could no longer have the control to do the slow extension to lower myself and straighten my arms. Surprisingly, I was able to continue with another 20 minute workout after that which included banded pull-ups and “wall balls”.

    When Did You Notice Something Was Wrong? 

    Immediately after the workout, my arms started to feel dysfunctional. I couldn’t control the muscle enough in a bent position to wash my face or my hair. I thought it was just a more extreme version of the days you walk out of the gym feeling a little “wobbly” or like “jell-o” after a tough workout. 

    That was on a Tuesday morning. I assumed the soreness would settle within a day or two like it usually does. Wednesday, I noticed I had trouble lifting my tote from the ground. My arms were struggling to function. Small movements, like opening the car door handle, felt painful and my biceps and the muscles around my elbow were swollen.

    I soon realised this was not just usual soreness. It felt like my muscles were broken. My husband, a regular CrossFitter, had heard of rhabdomyolosis but he thought the tell-tale sign was dark or coloured urine. My urine looked completely normal all week, so we ruled this out as a possibility.

    By Friday evening I was beginning to feel lethargic and like I wanted to stay in bed. I felt drained of energy and my arms were still swollen (4 days post workout). I began Googling why I would still be sore and swollen 4 days after a workout, and LUCKILY I stumbled upon an article titled “The negative pull-ups workout that nearly killed me”. The author’s story sounded exactly like what I had experienced.  (Article:

    It was around 9pm when I read that article and we headed straight to Canossa Hospital to request a blood test. My husband and I had “rhabdomyolosis” and the name of the blood test written down in case the doctor on duty wasn’t aware of the condition. (The blood test is for creatine phosphokinase or CPK).

    Thankfully the doctor knew exactly what it was and called for the blood test immediately. (Apparently, they get at least one case a week at Canossa). I was told the test results would be ready within 4 hours, so I could go home and wait for their phone call. I was woken at 2am by the nurse’s call telling me my levels were extremely high and I needed to be admitted ASAP. My CPK levels were at 17,000 U/L which carry risks of cardiac arrest and kidney failure. 

    I was met back at the hospital by a Nephrologist who then did further testing and monitored me daily.

    How Did Treatment Go? 

    The treatment was a slow, steady process. I was hospitalised for 5 days and on IV fluid drip the entire time. The slightest bit of dehydration could be dangerous because the muscle proteins are floating around the bloodstream which could literally choke the kidneys. The treatment plan was designed to flush the toxins from my blood. I was to urinate every 1-2 hours and ideally 400 -700ml each time. I had to measure how much I drank and urinated.

    How Long Was the Treatment? 

    Treatment lengths can vary. In my case the doctor agreed that I could go home if my levels hit 1000 or below (this is still 10x the normal range). Luckily, my kidneys did not show signs of damage, so as my CPK levels dropped, my condition was improving. My muscles were still weak and painful though. 

    How Long Did it Take to Recover? 

    It took 7-10 days for my muscles to feel normal and my energy levels to return. The doctor said I should avoid all arm exercises and general exertion until one month post-treatment. Until that point, there is a risk of the rhabdomyolosis recurring. If the muscles aren’t given enough time to heal and rebuild, they can fall apart again. The doctor told me, by the one month mark, I should have 30% of the strength back and within 3-6 months the muscles should regain 100% of their original strength. 

    How Do You Feel Now? 

    I feel ok, but have not attempted any serious arm exercises since. 

    What Precautions are You Taking to Avoid This Happening Again? 

    I’m focusing more on cardio rather than singling out individual muscles. But honestly, I started a new job 5 days after I was released from the hospital and have been juggling the balance of work and being a mom to 3 kids. Unfortunately, I haven’t made enough time to work-out as I would like. 

    Any Other Thoughts?

    My main advice would be to drop your ego at the door and not be afraid to stop a workout mid-way if you sense something doesn’t feel right. 

    Rhabdomyolosis is a scary thing and can very easily happen to ANYONE. I have no ego when it comes to working out and I’m the first to put my hand up and ask for a modified workout if I need it, and it still happened to me. I didn’t know the signs, and honestly, even if I did and stopped my workout at that point, it would have been too late.

    The moment I felt I was just “dropping” from the bar and couldn’t do the slow release, that was the sign my muscles had been injured. It was not painful and not an identifiable moment like with other injuries. And I was able to continue my work-out after that! 

    The thing is, I don’t know what I would have done differently on that day. I had been working out for almost 8 months in that gym and was always very cautious while doing a modified version of what everyone else was doing. What I have learned through reading about rhabdomyolosis is it’s not necessarily the movement or the heavy weights that cause it. It’s the extreme repetitions of the movement that usually does it. 


    * A previous history of rhabdomyolysis also increases the risk of having rhabdomyolysis again.

    Rhabdomyolysis Signs and Symptoms

    Signs and symptoms may be hard to pinpoint as they can be subtle, non-specific and could mimic other conditions. Symptoms may occur in one area of the body or affect the whole body. Additionally, complications may occur in early and later stages.

    The “classic triad” of rhabdomyolysis symptoms are:

    • muscle pain
    • muscle weakness
    • dark coloured urine or decreased urination

    Other symptoms may include:


    Blood tests for creatine kinase (a product of muscle breakdown) and urine tests for myoglobin (a relative of hemoglobin that is released from damaged muscles), can help diagnose rhabdomyolysis. Additional tests may be performed to rule out other problems, confirm the cause of rhabdomyolysis, or check for complications.


    Early diagnosis and treatment of rhabdomyolysis and its causes are keys to a successful outcome. You can expect full recovery with prompt treatment. Doctors can even reverse kidney damage.

    If you have rhabdomyolysis, you will be admitted to the hospital to receive treatment for the cause. Treatment with intravenous (IV) fluids helps maintain urine production and prevent kidney failure.

    Most causes of rhabdomyolysis are reversible.

    If you’re starting a new workout routine and doing it gradually, the risk of rhabdomyolysis is extremely low. It typically only occurs after extreme exercise, but some other things can increase your chances of it:

    • Being dehydrated
    • Exercising while you’re on medications like ibuprofen or Aleve
    • Exercising in the heat

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    Tiffany Beeson
    Tiffany Beeson is a content writer, editor, and copywriter covering health, parenting, education, families, and lifestyle plus global real estate and finance sectors. Tiffany has contributed to large global publications in scientific research and holds a Master of Science degree in Physiology. She spent over 18 years of her career in the field of clinical research in the USA, Hong Kong, Europe, and Canada - writing protocols, standard operating procedures and data reports.

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