According to a new study published in The Lancet Haematology, recombinant human erythropoietin (rHuEPO), a performance augmenting drug has little effects on high-intensity laboratory cycling test among well-trained amateur cyclists; yet in the laboratory time trial test and endurance road-race up Mont Ventoux (France), the augmenting effects were typically undetectable.
The participants of the double-blind randomized trial consisted of 48 well-trained amateur male cyclists in the age group of 18–50. Although there were no records of any antagonistic events, a possibility in the increased risk of coagulation is expected due to the rise in levels of hemoglobin and adhesion molecules caused by the drug.
The suggestion that the results are contradictory to the prerogatives of the prodigious effects seen in famous literature, and possess the chance for reduced incentives to use rHuEPO for athletes, authors said.
Of the total participants involved in the trial, 24 were provided with a weekly injection of rHuEPO and the rest were given a placebo of saline solution for a period of 8 weeks. Consistent doses were provided for the sample along with professional cycling training. The experiment aimed at increasing the hemoglobin levels in the participants of the first group by 10–15% compared with at the beginning of the study.
A series of tests were involved in the trial through which various performance parameters were evaluated. A ramp test that took nearly 30–50 min was included in the first high-intensity laboratory test, where the pedaling resistance was made low at every 5 min till exhaustion. In the second test, which was similar to a time trial, a 45-min endurance test was involved at the maximum power output. The final test, which included a 21.5 km road-race up Mont Ventoux, preceded by 110 km cycling, was done after 12 days of the final injection.
Exercise performance, the prime outcome in both the tests, was calculated using multiple measures. Researchers also calculated the secondary outcomes which was the Mont Ventoux race times.
There is no difference seen in gross efficiency, heart rate, and other respiratory parameters among the groups. Compared to the placebo group, the rHuEPO group reported higher mean hemoglobin concentrations, maximal power output, maximal oxygen consumption, and performance parameters in the high-intensity laboratory test.
The mean power output, consumption of oxygen, and Mont Ventoux race times of approximately 1 hr and 40 min did not vary among the groups for endurance tests. Similarly, for cycling economy, mean heart rate, and lactate levels.
Among the two groups, no difference was recorded in adverse events, however, there was a significant increase in E-selectin and P-selectin—endothelial function markers in the group that used rHuEPO.
Mr Jules Heuberger, lead author, Centre for Human Drug Research, Leiden, Netherlands, said:
Our study was designed to apply the gold standard of clinical trials to doping research, and we found that while rHuEPO increased performance in a laboratory setting on high intensity tests, the differences largely disappeared in endurance tests, and were undetectable in a real-world cycling race.”
Using drugs to enhance performance is a main problem in several competitive sports and over 300 substances are in the prohibited list for 2017. Yet, there is limited scientific proof about these substances, partially because it is not possible to carry out tests with professional cyclists as they are subjected to anti-doping rules.
The drug rHuEPO is expected to increase the delivery of oxygen to the muscles, thereby improving exercise performance as it promotes the production of red blood cells. High-intensity test with less time duration was involved in most previous studies on rHuEPO. Studies aiming at the effects of rHuEPO on more significant endurance race tests were very less.
Although the study findings can be applied to the highest performing participant (cyclist) in the study, whether the study results can be applied to a professional cyclist remains a question, Heuberger added.
The clinical trials on possible doping substances can be accomplished as per the study results and further research can give clear information to anti-doping agencies and let the athletes and their medical staff know about doping risks.
Although the study is comparatively small, it is larger than most of the evidence published till date, which can go against claims and may decrease the incentives for athletes using rHuEPO, the authors said.