Never do Crossfit!
Crossfit has three strikes against: 1) It’s a fad (albeit a very long lived one), 2) it exposes people to unnecessary risk and injury, and 3) it gives “certifications” to “trainers” after only two days of instruction. Because of this, I will never endorse Crossfit. I think it’s dangerous, irresponsible, and cult-like. I would strongly suggest you not drink the Cool Aid.
Rhabdomyolysis is very rare in the general population; however, it’s so common amongst Crossfitters that they have to be constantly reminded that it’s a potential risk. When you work past your comfort zone, you create microtraumas to your muscles. That’s really important. That’s where the growth happens. It’s where the healing happens, and it’s where new strength develops. So you do need that to make gains. However, rhabdomyolysis is severe, and the microtraumas are so bad that the muscle cells actually split open and die. They then spill their contents into the blood. That’s really dangerous, because the kidneys were never meant to filter that out of your blood.
The kidneys then get backed up. You can have kidney failure. Other organs can then fail. Some people have needed amputations. Some people have died.
These are the extremes that people in Crossfit will push you toward. It’s irresponsible. What’s worse is that they make fun of people when they approach that level of pain, and even encourage them to work through it anyway. They even have a cartoon mocking people who complain about pain called Uncle Rhabdo The Clown. I cannot repeat it enough: “No Pain, No Gain” is a complete falsehood. Work toward growth, not injury. The former creates discomfort, the latter creates pain. You have to learn to distinguish the two.
Also, according to Bryan Pyfferoen at www.TheBarbellSpin.com, the 2017 Crossfit California Regionals have already seen 36 pectoral tears as of May 30. He does not mention the number and type of other injuries specifically, but it would be safe to assume there are many. What’s even more disturbing than these huge number of serious accidents is the overly long essays many of the participants have written about their injuries. Many read as if they are apologizing for committing treason. Grape was definitely their favorite flavor.