Abstract
Rhabdomyolysis is characterized by the release of muscle cell components into circulation following muscle cell injury. Common causes include trauma and compression, exposure to drugs and toxins, and intense physical exercise. This study depicts a case of exercise-induced rhabdomyolysis following a cycling class. A 24-year-old African American woman presented to the emergency department with a one-day history of bilateral lower extremity myalgia, weakness, and stiffness, predominantly on the right side. She had participated in a one-hour morning cycling exercise class the previous day and came to the emergency department the following morning after noting dark-colored urine. Her initial creatine phosphokinase (CPK) level was 53,601 IU/L, leading to a diagnosis of exertional rhabdomyolysis. Her CPK continued to rise, peaking at 175,294 IU/L approximately 34 hours after admission. Serum chemistry, liver function, and clinical complications were closely monitored during the patient's hospitalization. The patient responded well to IV fluids, showed clinical improvement, and did not require additional interventions or specialist consultations. Exertional rhabdomyolysis is increasingly common following exercise and may lead to serious complications. Prognosis in rhabdomyolysis is best when treated early and aggressively.