Running and other high-intensity exercise can trigger a potential “silent killer” condition: rhabdomyolysis, often also called “rhabdo,” a disease in which the contents of muscle cells leak into the bloodstream.
writing Runner’s WorldProfessor William O. Roberts said: “Almost everyone who exercises to improve performance releases or leaks creatine kinase (CK) into the bloodstream. Athletes with large muscle mass may have baseline CK levels above the generally accepted normal range. However, this becomes problematic when muscle cells release compounds such as potassium and myoglobin, causing complications.”
But, he adds, “You’re unlikely to develop rhabdomyolysis unless you significantly increase your training volume or intensity, which can lead to all kinds of overuse injuries. The key to safe high-intensity interval training is to gradually increase the volume and difficulty, allowing your muscles to adapt to the load over time.”
Severn Pathology, North Bristol NHS Trust, reports that the main causes of rhabdomyolysis are “direct muscle trauma resulting in pressure” and crush syndrome, which develops after a pressure injury to skeletal muscles, excessive muscle activity, electric shock, etc. Symptoms include muscle cramps and pain that are worse than expected, dark urine, and feelings of weakness and fatigue.
The Centers for Disease Control and Prevention (CDC) says symptoms can appear any time after a muscle injury, adding that “in some people, symptoms may not begin to appear until several days after the initial injury.”
“If you experience these symptoms at any time, do not ignore them – seek medical attention immediately. Early diagnosis means early start of treatment, increasing the chances of recovery without permanent health effects.”
