Is CrossFit Dangerous for Beginners? Risks and How to Start
CrossFit itself spread the image of a clown on dialysis to warn about a specific risk: rhabdomyolysis. Here we explain what it is, what the benefits of intense training are and how to get started safely.
What CrossFit and HIIT Are
CrossFit combines high-intensity interval training, known as HIIT, with weightlifting, gymnastics and running.
A class works your heart, your strength and some mobility. The toughest part usually lasts less than twenty minutes.
How Much Intense Training Delivers
In 2016, McMaster University had sedentary men cycle for twelve weeks. One group did three ten-minute sessions a week, with just one minute of sprinting in total. Another group did forty-five-minute sessions at a moderate pace. Both improved their aerobic fitness almost equally.
As an estimate, an hour-long class can burn between 400 and 700 kilocalories, depending on each person's weight and pace.
Three classes a week usually cover what the WHO recommends: 150 minutes of moderate activity or 75 minutes of vigorous activity, plus strength exercises two days a week. The WHO also links regular exercise to lower anxiety and depression.
Rhabdomyolysis: The Risk "Uncle Rhabdo" Warned About
The clown was called "Uncle Rhabdo" and warned about rhabdomyolysis. In this injury, muscle breaks down and releases myoglobin, a protein that can damage the kidneys.
The warning signs are cola-coloured urine, disproportionate pain and swelling. They can appear anywhere from a few hours to three days after the exertion. If you notice them, go to the emergency room.
It typically occurs with the first big effort after months without training, especially in hot conditions and with poor hydration.
Does CrossFit Cause More Injuries Than Other Sports?
The data do not single out CrossFit as the culprit. A 2013 survey estimated around three injuries per thousand hours of practice, a rate similar to that of weightlifting or gymnastics.
In addition, several published cases of rhabdomyolysis occurred during a first indoor cycling class. The danger lies not in the discipline, but in a beginner doing the volume of a veteran.
Who It Is For and Who It Isn't
It is a good option if you are short on time and find training in a group motivating.
It is not advisable without medical supervision if you have high blood pressure or heart problems, active joint injuries, or if you are pregnant with no previous experience of this kind of exertion. If you are over forty and have been inactive for a while, check with your doctor first.
Three Rules for Starting Safely
To get started, all you need is flat-soled shoes and water.
Rule one: during the first month, do no more than three sessions a week, for example Monday, Wednesday and Friday. Muscle repairs itself during rest. Stringing hard days together builds up damage without giving you time to recover.
Rule two: scale every exercise. Ask the coach for less weight, a resistance band for pull-ups and a lower box. The shoulder and lower back get injured when fatigue breaks down your technique. Correcting it is exactly what you are paying for, between 80 and 150 euros a month.
Rule three: finish your first session wanting more, at an effort of seven out of ten, when you can still speak in short sentences. Drink water and, the next day, check the colour of your urine.
Frequently asked questions
What is rhabdomyolysis?
It is the breakdown of muscle, which releases myoglobin, a protein that can damage the kidneys. It typically occurs after a first big effort following months without training.
What are the symptoms of rhabdomyolysis?
Cola-coloured urine, disproportionate pain and swelling, anywhere from a few hours to three days after exercise. If they appear, you need to go to the emergency room.
How many times a week should I do CrossFit when starting out?
During the first month, a maximum of three sessions a week, with rest days in between.
Does CrossFit cause more injuries than other sports?
A 2013 survey estimated around three injuries per thousand hours, a rate similar to that of weightlifting or gymnastics.
Informative article written with the help of AI tools from the verified script of the video. The video is in Spanish.