Calling b.s on this one .
not being nasty this is highly probable.
the reason he destroyed his kidneys was
the rampant doping in 2012 .........
Kids this is one of risks of taking to many steroids that and liver damage.
In his case more than likely just took far to much testosterone leading up to 2012.
You do know that the kidneys have to filter
blood every pass and only made to filter
out certain levels of hormones as norm.
but go way beyond norm for testosterone and metabolites and can effect function.
especially if toxicity in body.
Anyway in short sprints not great burden put on kidneys as event.
Would be impressed ,as jus not possible if
longer distance dealing with lactate ,etc,
recovery ,dehydration and fact produce
epo there and so on.
Besides fact still an igf-1 doper .