RUNNING MARATHONS COULD lead to short-term kidney damage, according to a new study from Yale University.

The study was published this week by the American Journal of Kidney Diseases. Although kidneys of the examined runners fully recovered within two days post-marathon, the study raises questions concerning potential long-term impacts of distance running.

While previous studies have focused on the effects of strenuous work on kidney health, very little is known about the effects of marathon running.

A team of researchers led by Professor of Medicine Chirag Parikh, MD studied a small group of participants in the 2015 Hartford Marathon. The team collected blood and urine samples before and after the 26.2-mile event. They analysed a variety of markers of kidney injury, including serum creatinine levels, kidney cells on microscopy, and proteins in urine.

The researchers found that 82% of the runners that were studied showed Stage 1 Acute Kidney Injury (AKI) soon after the race. AKI is a condition in which the kidneys fail to filter waste from the blood.

The researchers stated that potential causes of the marathon-related kidney damage could be the sustained rise in core body temperature, dehydration, or decreased blood flow to the kidneys that occur during a marathon.

While the measured kidney injury resolved within two days post-marathon, the study still raises questions about the effects of repeated strenuous activity over time, especially in warm climates.

“We need to investigate this further,” said Parikh. “Research has shown there are also changes in heart function associated with marathon running. Our study adds to the story — even the kidney responds to marathon-related stress.”

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