In the context of CrossFit or other high-intensity training methods, you will sooner or later come across the term rhabdomyolysis.

Although this condition is very rare and only caused by training in 1% of cases, it should still be taken seriously.

In this blog post, we’ll explain what it’s all about, which symptoms indicate it, and what to do in an emergency. Please note that this information does not constitute medical or professional advice. In case of any suspicion, you should immediately see a doctor*.

What is Rhabdo?

Rhabdomyolysis is a breakdown of skeletal muscle, which leads to the release of muscle components. This can cause kidney damage (known as crush syndrome) and other complications (electrolyte imbalance, disseminated intravascular coagulation, etc.). In this case, medical assistance is absolutely and immediately necessary!

Causes

Basically, there is a distinction between traumatic, non-traumatic, exertion-related, and non-exertion-related rhabdomyolysis. Exertion-related rhabdomyolysis can develop from muscle damage due to excessive or overly intense training. This type of rhabdomyolysis is extremely rare. However, we want to make you aware of it because your health comes first.

Symptoms

We distinguish non-specific symptoms such as fever, vomiting, diarrhea, nausea, and severe fatigue (which could also be signs of other illnesses) from specific symptoms. Swollen, soft, painful muscles are clear signs of rhabdomyolysis. If you have muscle pain that is distinctly different in type and intensity from typical soreness, these are further warning signals. At the latest, if you notice dark red-brown urine, you must see a doctor immediately. This symptom indicates that acute kidney failure is imminent or has already occurred. Home remedies like “drinking plenty of fluids” won’t help here.

All athletes who push themselves too hard and ignore all the above-listed warning signals can be affected. Not only untrained people or those resuming training after a long break can be at risk. Even experienced athletes can be affected. Therefore, it is essential: if your body tells you, “Take a break immediately!” – listen to it.

We know that our athletes push each other to peak performance in groups – but health must NEVER suffer due to group dynamics or misguided ambition. We trainers ensure you don’t overexert yourself, but you are the best judge of when you have reached your personal limit.

Prevention

Experienced athletes generally know their bodies and limits well and should always strive to improve by introducing new training stimuli. Maintaining the health of the entire musculoskeletal system comes first – so it’s essential to train wisely. In our articles on recommended training frequency and biological adaptation processes through training, you’ll find more interesting information on how to structure your training at different phases and the role of recovery (which, as you know, is essential!).

Don’ts!

Constantly training beyond soreness can lead to serious muscle fiber injuries and induce trauma in them.

Training combined with alcohol, drugs, (strong) medications, or during illness is – as common sense dictates – a complete no-go! This combination not only increases the risk of rhabdomyolysis but also poses many other (unpredictable) dangers to your health. Not to mention steroids, anabolic agents, or any dubious performance enhancers from the internet!

Also, be aware that the strain on the body is especially high when training in extreme temperatures. This applies to both heat and cold. Besides possible circulatory issues, respiratory inflammation, and potential acute illnesses, the body cannot appropriately process training stimuli under extreme conditions, which can lead to adverse reactions like muscle breakdown.

We cannot stress enough: listen to your body and its warning signs! Developing a sense of body awareness is part of an athlete’s training. Strong pain and exhaustion simply call for a break.

What should I mention to the doctor?

Be sure to inform your doctor of your suspicion. As mentioned, rhabdomyolysis is a very rare condition that is often not considered.

A mild case of rhabdomyolysis is often only identified by elevated concentrations of enzymes in the blood that are usually found in muscles. These enzymes include creatine kinase (CK) and lactate dehydrogenase (LDH). High levels of myoglobin in the blood also lead to myoglobinuria, or myoglobin being excreted through the kidneys, which causes the urine to turn red-brown. If your doctor confirms your suspicion, they will likely perform a creatine kinase (CK) test. The blood level of this enzyme provides the most critical clue for diagnosing rhabdomyolysis.

If you suspect you may have rhabdomyolysis, first consider the following questions. If several points apply to you, consult a doctor immediately:

1. What signals/symptoms have I noticed?

Specific:

  • Severe muscle pain, distinctly different from typical soreness
  • Severe muscle pain lasting more than two days and worsening rather than improving
  • Soft, limp, swollen muscles
  • Loss of muscle tone
  • Red-brown urine

Non-specific (may also indicate other conditions):

  • Fever
  • Nausea
  • Diarrhea
  • Vomiting
  • Fatigue

2. How did I train and what?

  • Did I try/apply a new type of training?
  • Did I strain specific muscle groups excessively?
  • Did I resume training after a long break and go all-in?
  • Was the training intensity and volume unusually high?
  • Did I train despite severe muscle soreness and barely, if at all, recover?

3. Did I train in extremely high or low temperatures?

4. Do I or someone in my family have a health condition?

  • Muscle disorders or muscle trauma?
  • Metabolic diseases?
  • Acute infection?
  • Blood disorders?
  • Poisoning?
  • Were or are there chronic pains?
  • Muscle limitations?

5. Am I currently taking any medication? (e.g., pain relievers, analgesics, antibiotics, sleep aids, etc.?)

6. Did I consume drugs, alcohol, or other substances (e.g., stimulants or performance enhancers) on the day of or the days before training?

7. When did the first symptoms (muscle pain, fatigue, urine discoloration, etc.) appear?

8. How much time passed between training and the first symptoms?

*please also refer to §4, paragraph 13 of our terms and conditions (health requirements)