Hein F.M. Lodewijkx^1,, Bram Brouwer¹, Harm Kuipers², René van Hezewijk¹

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 (VO_2max) and maximal aerobic power output (W_map). 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 VO_2max, 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 W_map, the increase was M = 26W with the strongest post test performance of M = 398W observed in similar studies as VO_2max. Percents improvement from pre to post tests varied between M = 6–7% (VO_2max), and M = 7–8% (W_map). The largest improvement in VO_2max 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.

aerobic performance, epo doping, meta-analysis, professional road racing