The physical stress of running a marathon can cause
short-term kidney injury. Although kidneys of the
examined runners fully recovered within two days
post-marathon, the study raises questions concerning
potential long-term impacts of this strenuous
activity at a time when marathons are increasing in
While past research has shown that engaging in
unusually vigorous activities in warm climates can
damage the kidneys, little is known about the
effects of marathon running on kidney health.
A team of researchers led by Professor of Medicine
Dr. Chirag Parikh 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 analyzed 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 kidney responds to the physical stress of
marathon running as if it’s injured, in a way that’s
similar to what happens in hospitalized patients
when the kidney is affected by medical and surgical
complications,” said Parikh.
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” said Parikh.
Other study authors are Sherry G. Mansour, Gagan
Verma, Rachel W. Pata, Thomas G. Martin, and Mark A.
The study was published March 28 by the American
Journal of Kidney Disease.
For more information
Kidney Injury and Repair Biomarkers in Marathon
American Journal of Kidney Disease