PARIS, Dec 6, 2012 – Cyclists who dope themselves with EPO may not
gain any performance advantage even though they are putting their health at
risk, scientists said on Thursday.
In a review of the evidence, a team of European researchers scoffed at the
entrenched notion that EPO gives cyclists an edge.
And they pointed out that the drug has many perils for those who use it
illicitly, including blood clots that can cause strokes and heart attacks.
“Athletes and their medical staff may believe EPO enhances performance, but
there is no evidence that anyone performed good experiments to check if EPO
would actually improve performance in elite cyclists,” said Adam Cohen, a
professor at the Centre for Human Drug Research in the Netherlands.
EPO — erythropoietin — is a natural hormone, produced in the kidneys,
which helps regenerate the red blood cells that transport oxygen around the
A man-made version of the hormone is licensed for treating renal patients
to help them combat anemia.
As early as 1990, the drug appeared on the International Olympic
Committee’s banned list, given the suspicions that by increasing red-blood
cell mass, it also boosts exercise capacity.
EPO then engulfed professional cycling, breeding a scandal that erupted
this year when Lance Armstrong was stripped of his record seven Tour de France
But, said the new study, no solid evidence exists to back the belief that
EPO is as effective as dodgy trainers and team doctors believe.
And, it added, there are plenty of reasons to say the faith is as dangerous
as it is misplaced.
Cohen’s team trawled through published studies that tested EPO’s effect on
healthy cyclists but found none which had participants of competition level,
whose genetic profile and training programs differ from those of sub-elite
The big belief behind EPO is that it improves maximal oxygen uptake —
known in scientific parlance as VO2 max — and thus boosts power output.
But Cohen found no proof for this, at least as far as pro cycling is
In tests, cycling volunteers were usually assessed for VO2 max for just 20
minutes or so, a far cry from a five-hour grind of a cycling race.
In any case, said the study, VO2 max is only a minor factor in the
performance of endurance cyclists.
Only small segments of professional cycling races are cycled at such severe
intensities that VO2 max is decisive. There are many other factors, none of
them influenced by EPO.
They include the blood lactate threshold, which determines the point at
which muscles tire; work economy, which is the efficiency of the metabolic
system to convert energy into movement; increased cardiac volume; and the
quantity of muscle mass available for sustained power production.
“There is no scientific basis to conclude EPO has performance-enhancing
properties in elite cyclists,” is the blunt conclusion of the study, which
appears in the British Journal of Clinical Pharmacoloy.
“Additionally, the possibly harmful side-effects have not been adequately
researched for this population, but appear to be worrying at least.”