Rhabdomyolysis, or rhabdo, is the breakdown of muscle tissue that leads to the release of muscle fiber contents into the blood. High intensity, repetitive movement exercises can lead to the syndrome.
"A lot of fitness trainers out there still believe that you have to go hard and heavy with exercise for it to be effective and that's actually not true. Especially when it comes to a beginner," said exercise physiologist Joe Cannon.
Cannon has been studying rhabdo for more than a decade and has seen an increase in the number of cases.
"I do believe it's a result of the fact that there's more high intense exercise classes and programs out there than there were when we originally talked four years ago," he said.
Symptoms include muscle swelling, muscle weakness and constant muscle soreness that begins shortly after exercise.
"Go slow. Don't jump into the new greatest exercise class or exercise program out there," Cannon advised. "Again, it comes back to listen to your body, do a little bit at a time, don't try to last an hour in the gym if you haven't been to the gym ever in your life or for a very long time."
And don't feel pressured to complete an entire exercise class.