Freebie Rhabdomyolysis: A Public Health Concern. Spin Class-Induced Rhabdomyolysis.

Background: Rhabdomyolysis is a pathologic condition in which intracellular muscle constituents leak into the blood circulation. It is usually caused by muscle trauma. "Spinning" is an indoor form of cycling where participants use a special stationary exercise bicycle with a weighted flywheel and undergo high-intensity cycling classes focusing on endurance. There have been several case reports in the literature of exertional rhabdomyolysis following spin class.

Methods: Our nephrology practices have diagnosed a number of cases of symptomatic patients presenting to our emergency departments following their first spin classes, with histories and creatinine phosphokinase levels diagnostic of exertional rhabdomyolysis.

Results: We present 3 unusual cases of exertional rhabdomyolysis, each occurring after a first spin class. In the first case, rhabdomyolysis developed following 15 minutes of spin class. In the second case, it occurred in a young individual who exercises regularly. In the third case, the patient developed biopsy-proved acute kidney injury secondary to exertional rhabdomyolysis and required hemodialysis.

Conclusion: The high-intensity exercise associated with "spin class" comes with significant risks to newcomers.