An extreme athlete has been admitted to hospital after running 524 miles on a treadmill in seven days.
'Adventureman' Jamie McDonald broke a world record with his mammoth show of endurance.
The 32-year-old smashed the previous best effort by seven miles in a super-human achievement that ended on Monday.
But a home visit to the exhausted runner from a doctor led to blood samples being taken, Gloucester Live reports.
The medic claimed he was "disturbed" by his findings.
The possibility of stress fractures in his ankles was raised too.
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Today Jamie's social media channels were updated with a picture of him in a bed at Gloucestershire Royal Hospital.
The accompanying post said: "After a doctor's home visit to conduct a health check, Jamie's red blood cell count was found to be half what it was prior to the record.
"As well as this, his muscle enzyme (CK serum) levels are elevated, and more than 3x what they should be.
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“Under advice from the doctor, who said he was 'disturbed’ about the blood results and worried about what he's just put his body through, Jamie was admitted to Gloucestershire Royal Hospital last night, where he's being monitored and undergoing a few tests, including a CT scan, to ensure he's recovering as well as he possibly can be.
"Thank you for all of the messages asking after him, and we will update when he's ready to leave - we keep telling him that it's OK to be taking it easy given he's just done something literally no other human being in history ever has (!) - but he's keen to be back on his feet soon."
The athlete raised almost £55,000 for his charity, the Superhero Foundation, in the process, to help poorly children all over the world.
