Running marathons may cause short-term kidney injury: study

Planing to run a marathon? Think again, as the physical stress of running a marathon may cause short-term kidney injury, scientists including one of Indian origin have warned.
Researchers from Yale University in the US studied a small group of people participating in a marathon.
They collected blood and urine samples before and after the 26.2-mile event.
Researchers then analysed a variety of markers of kidney injury, including serum creatinine levels, kidney cells on microscopy, and proteins in urine.
They found that 82 per cent 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, researchers said.

"The kidney responds to the physical stress of marathon running as if it is injured, in a way that is similar to what happens in hospitalised patients when the kidney is affected by medical and surgical complications," said Chirag Parikh of Yale University.
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, researchers said.
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.

The study was published in the journal American Journal of Kidney Disease.