Marines at Highest Risk for 2 Lethal Heat-Related Conditions

Increasing Cases of Exercise-Related Health Risks in US Military

The US military has reported an upswing in two serious exercise-related medical conditions, rhabdomyolysis and hyponatremia, in the past four years. The Marine Corps has been particularly affected, reporting the highest incidence of these conditions.

Understanding Rhabdomyolysis

Rhabdomyolysis, often shortened to “rhabdo,” is a potentially life-threatening condition characterized by the rapid breakdown of muscle cells. The damage releases harmful substances into the bloodstream that can lead to electrolyte imbalances, kidney failure, and heart arrhythmia. This condition is commonly triggered by heat, strenuous exercise, or trauma.

Understanding Hyponatremia

Hyponatremia, on the other hand, is a condition resulting from a sodium imbalance in the body, typically caused by excessive consumption of fluids (water or sports drinks) before or during intensive physical activity. Like rhabdomyolysis, hyponatremia can also be life-threatening.

Incidence Rates across US Military

According to recent reports, the rate of rhabdomyolysis in the Marine Corps in 2023 was nearly five times that of the Air Force, Navy, and Coast Guard. The Army followed closely with the second-highest rate, reaching nearly three times that of the other three services. Recruits, non-Hispanic Black service members, and those in combat-arms specialties (infantry, artillery, combat engineering, and armor) exhibited the highest rates of rhabdo.

Furthermore, the Marine Corps also reported the highest incidence of exertional hyponatremia in 2023, with the Army and the Air Force reporting rates about two-thirds that of the Marine Corps. Women, recruits, service members in combat-arms positions, and troops over 40 years old in the northeastern US had the highest rates of hyponatremia.

Preventing Exercise-Related Health Risks

As both rhabdomyolysis and hyponatremia are largely preventable conditions, military leadership should remain vigilant about monitoring environmental conditions, hydration, troop fitness, and work-rest ratios. Proactive steps, such as preconditioning training and educating military personnel about the symptoms of these conditions, can significantly help in early identification and prevention, ultimately ensuring the health, performance, and combat effectiveness of US military personnel.

Further reading and medical studies on rhabdo and hyponatremia, along with other health conditions related to intense physical activities, can be found in the Medical Surveillance Monthly Report, published by the Armed Forces Health Surveillance Division.