5.MAR.2021 4 MIN READ | 4 MIN READ

CrossFit and spin classes are increasingly popular and becoming mainstream exercises for those looking to maintain fitness or lose weight. However, the uninitiated can quite literally exercise themselves to death.

These strenuous exercise programmes put a lot of strain on the muscles. Gym goers new to the classes, even those who may be super fit, can be at risk of exercising themselves to death if they push themselves beyond their endurance levels and fail to listen to their body.

How can a simple gym class be so dangerous?

Many participants adopt a mentality to “go big or go home”, fuelled by high-intensity workout music and encouraged by the enthusiasm of fellow attendees to power through the gruelling session. In spin classes, attendees often have their cycling shoes locked onto the pedals, which may discourage them from pausing to take necessary breaks. In such an intense atmosphere, newbies may find themselves getting carried away and pushing themselves a little too hard.

Of course, if you’re pacing yourself well and not pushing yourself past your body’s limits, attending a new class for the first time isn’t going to put your health at risk. You may experience muscle soreness for a couple of days afterwards as your overused muscles start to heal. However, for an unlucky few, overexertion can lead to muscle breakdown and muscle death, a rare condition called rhabdomyolysis. The resulting toxicity in the body as the muscles break down may lead to kidney failure and even death.

What is rhabdomyolysis?

Rhabdomyolysis, brought on by overexertion during exercise, causes the muscle cells to break down. As this happens, a protein called myoglobin is released into the bloodstream. If myoglobin is released in large quantities, the kidneys are unable to remove it from the blood fast enough and flush it out of your system through urination. The extra stress placed on the kidneys damages these vital organs and kidney failure and death can occur.

Who is at risk?

Who is at risk?
While rhabdomyolysis is rare, it can happen to anyone. You are more susceptible if you:

  • are a first-time endurance athlete: Particularly if you are pushing yourself too hard without resting during high intensity exercise routines such as marathon running and spin classes
  • are a firefighter: Overheating in hot temperatures while applying physical exertion puts you at risk
  • are a member of the military: Particularly when in a boot camp and made to undergo intense training that your body is not used to
  • have an inherited muscle disease such as muscular dystrophy
  • have certain metabolic or mitochondrial disorders
  • are taking certain drugs and/or recreational substances like amphetamines, cocaine: Some drugs increase the risk of muscle breakdown, while certain recreational substances induce a 'high' state which can cause the users to ignore their over-worked muscles

How can I tell if I have rhabdomyolysis?

It is common to have muscle soreness and associated aches and pains for a few days after doing any rigorous exercise that you are not used to. However, if the aches and pain persist beyond a couple of days and you experience any of the following additional symptoms, see a doctor and discuss getting tested for rhabdomyolysis.

  • Muscle swelling
  • Weak, tender and sore muscles
  • Dark tea-coloured urine
  • Decreased urination
  • Dehydration
  • Nausea
  • Loss of consciousness

Early diagnosis and treatment are essential for this potentially fatal condition.

What happens if I’m diagnosed with rhabdomyolysis?

As rhabdomyolysis is a potentially life-threatening condition that can cause your kidneys to fail if left untreated, you will be hospitalised immediately and given fluids and electrolytes intravenously to help your body rehydrate and to flush the toxins from your system. Your condition will be monitored for a few days in the hospital and, as you recover, you may be required to undergo physical therapy to help strengthen your weakened muscles.

If, however, you are diagnosed with kidney damage, you may need dialysis treatment temporarily to remove the toxins from your blood as your kidneys can no longer perform that function. This kidney damage, while usually temporary, does increase your future risk for chronic kidney disease.

Can rhabdomyolysis be prevented?

Can rhabdomyolysis be prevented?
The severity of muscle damage is inversely related to the cardiovascular and muscular fitness of the individual. By being aware that intense exercise has its risks, you can reduce the chances of developing exercise-related rhabdomyolysis by:

  • Starting any exercise programme, especially a new one, slowly and stopping when your body signals that it is too much. Don’t push yourself beyond safe limits.
  • Stay hydrated and avoid getting overheated. If you are exercising out in the sun, take breaks in the shade.

How long does it take to recover from rhabdomyolysis?

If you are one of the 65 – 85% who do not suffer kidney damage, you will recover but may experience lingering muscle weakness for several weeks afterwards. If your kidneys are damaged and you need dialysis, speak to your doctor about your long-term journey to recovery.

No exercise routine is worth damaging your health for. Know your limits and stop any exercise once you feel overstretched. It may be damaging to the ego, but that’s better than damaging your kidneys and potentially losing your life.

If you know you have overexerted yourself and are experiencing symptoms that could indicate rhabdomyolysis, visit the A&E immediately.


Article reviewed by Dr Angeline Goh, renal medicine specialist at Mount Elizabeth Hospitals


Retrieved 25 February 2021 from https://www.webmd.com/fitness-exercise/news/20180222/exercising-yourself-to-death-the-risk-of-rhabdo

Retrieved 25 February 2021 from https://my.clevelandclinic.org/health/diseases/21184-rhabdomyolysis

Angeline Goh Ting Hui
Mount Elizabeth Hospital

Dr Angeline Goh is a renal medicine specialist at Mount Elizabeth Hospital, Singapore.