CrossFit and rhabdomyolysis: A case series of 11 patients presenting at a single academic institution

Abstract

Objectives: CrossFit is an increasingly popular high intensity work out program geared towards high repetition and intensity done in short intervals. Recently, documented cases of rhabdomyolysis (muscle necrosis and extreme muscle breakdown) after CrossFit participation have become increasingly concerning to physicians and participants alike.

Design: Retrospective cohort study.

Methods: All patients who presented to the main hospital at a major academic center complaining of an injury sustained performing CrossFit between June 2010 and June 2016 were identified by the key phrases 'CrossFit', 'crossfit', 'Crossfit' or 'cross fit'.

Results: 523 patients incurred injuries associated with CrossFit activities. 11 patients presented to our institution ultimately received a diagnosis of rhabdomyolysis (2.1%). The average age of Rhabdomyolysis patient was 34.9 years, with 81.9% of patients being male. The average BMI was 24.2, and the average experience level was beginner (54.5%). The most common presenting symptom was dark urine (90.9%), followed by upper extremity pain (54.5%). Average symptom duration was 2.9days with 81.8% of patients presenting initially to the ED. The average hospital stay was roughly 2.9 days, and patients had an average of 1.44 clinical follow up visits.

Conclusion: CrossFit participation poses significant risks to participants including exercise induced rhabdomyolysis. Further study is needed in order to raise awareness of this issue and further quantify risk factors that may promote injury during participation.

Keywords: CrossFit; Exercise induced injury; High-intensity workout; Rhabdomyolysis.