Subjecting your body to excessive exercises after a long time of inactivity may not just cause discomfort, it can be fatal. Taking to X, internal medicine expert Dr Priyam Bordoloi shared an anecdote.

After spending several months without exercising, a man suddenly attempted an intense two-hour training session. Soon afterward, he developed severe muscle soreness that felt far worse than the typical discomfort experienced after exercise.

The following day, he noticed that his urine had become unusually dark, resembling the color of cola. Assuming it was nothing serious, he chose to ignore the warning sign and went to bed.

During the night, he suffered a fatal cardiac arrest.

How could a workout lead to such a devastating outcome?

This scenario highlights a critical medical emergency that is important for everyone—from the general public to healthcare students—to understand. The following questions and answers explain the condition in simple terms.

What is the medical condition?

The condition is called rhabdomyolysis, a potentially fatal disorder in which damaged skeletal muscle rapidly breaks down, releasing harmful substances into the bloodstream.

What happened inside the body?

The individual's muscles were not prepared for such strenuous physical activity after a prolonged period of inactivity. The excessive strain caused large numbers of muscle fibers to rupture and die.

As these muscle cells disintegrated, they released myoglobin, an oxygen-binding protein, into the circulation. High levels of myoglobin can overwhelm the kidneys, blocking and damaging their filtering system. One of the earliest warning signs is urine that becomes dark brown or cola-colored because of the large amount of myoglobin being excreted.

The danger does not stop there. Damaged muscle cells also release large quantities of potassium into the bloodstream. A sudden rise in blood potassium, known as hyperkalemia, can disrupt the heart's normal electrical activity. This disturbance may trigger life-threatening rhythm abnormalities that can rapidly progress to cardiac arrest.

Could this emergency have been treated?

In many cases, yes. Immediate medical attention after noticing dark-colored urine can significantly improve the chances of recovery.

Doctors typically begin aggressive intravenous fluid therapy to increase urine production and help flush myoglobin from the kidneys, reducing the risk of permanent kidney injury. Early treatment also helps dilute excess potassium and allows healthcare teams to monitor and correct dangerous electrolyte imbalances before they affect the heart.

How can rhabdomyolysis be prevented?

Do not begin with prolonged, high-intensity workouts after weeks or months of little or no physical activity. Increase exercise duration and intensity gradually so your muscles can adapt safely.
Stay well hydrated before, during, and after strenuous exercise, particularly in hot weather or during extended training sessions.

Seek emergency medical care immediately if severe muscle pain or swelling is accompanied by dark, tea-colored, or cola-colored urine, reduced urine output, or extreme weakness. These symptoms may indicate rhabdomyolysis and require urgent evaluation and treatment.

Although rhabdomyolysis is uncommon, recognizing its warning signs and seeking prompt medical care can prevent serious complications such as acute kidney injury, dangerous electrolyte disturbances, and potentially fatal heart rhythm abnormalities.