RENO, Nev. -- A popular fitness program CrossFit is being linked to a potentially fatal condition caused by people pushing their bodies so hard that their muscle cells actually burst.
CrossFit is a military-style exercise that pushes your body to the brink, but some health experts say the workout can cross the line if you aren't careful.
Eric Robertson, a professor of physical therapy at Regis University wrote about a rare and potentially fatal condition called Rhabdomyolysis that can afflict some people who do CrossFit.
He wrote "Rhabdo isn't a common condition, yet it's so commonly encountered in CrossFit that they have a cartoon about it."
Rhabdo is when skeletal muscles get damaged and release proteins too quickly into the blood. This can lead to kidney problems and failure.
Russell Berger, a CrossFit course supervisor and spokesperson, says Rhabdo is not unique to crossfit. Berger says, "There are cases of Rhabdo from football players, marathon runners to military trainees, to body building communities."
Berger says one of CrossFit's main goals is to raise awareness about Rhabdo and how to prevent it.