Overestimated Effect of Epo Administration on Aerobic Exercise Capacity: A Meta-Analysis

Recent studies examining the relationship between epo doping and aerobic performance (the EDAP–relationship) yield conflicting results. To resolve this inconclusiveness in an empirical way, we conducted a meta–analysis on 17 laboratory studies and assessed effect sizes (unbiased d, r and r2) of the epo–induced improvements in aerobic exercise capacity measured by maximal oxygen uptake (VO2max) and maximal aerobic power output (Wmap).The fixed, pooled EDAP effect size estimates were moderate, d = 0.41–0.49, r = .19–.44, and r2 = .04–.19, revealing a shift of approximately half SD in performances of the epo–treated compared to the non–treated participants. As to VO2max, we observed the strongest post test performance (M = 64.39ml kg-1 min-1) in double blind, placebo controlled studies on performances assessed at sea level with an increase from pre to post tests of M = 4.02ml kg-1 min-1. Regarding Wmap, the increase was M = 26W with the strongest post test performance of M = 398W observed in similar studies as VO2max. Percents improvement from pre to post tests varied between M = 6–7% (VO2max), and
M = 7–8% (Wmap). The largest improvement in VO2max we found equals an increase in velocity of about 1km/h. Consistent with recent studies criticizing the EDAP-relationship our findings indicate that its strength is overestimated. In turn, this entails that the relationship between epo doping and cyclists‘ performances at real
contests is overrated too.