Stage Races1 Time Trials2
  Year N M (SE)3 95%-CI Year N M (SE)3 95%-CI
Across Races 1903-1914 16 0.21 (0.47)a -0.72–1.14 - - - -
1919-1929 22 1.48 (0.37)*a 0.75–2.22 - - - -
1930-1940 22 1.18 (0.64)a -0.08–2.43 1933-1942 9 1.46 (0.19)*b 1.07–1.86
1946-1952 18 0.93 (0.42)*a 0.11–1.75 1946-1952 15 1.10 (0.13)*b 0.85–1.35
1953-1962 28 0.26 (0.33)a -0.40–0.91 1953-1962 24 0.73 (0.10)*b 0.52–0.93
1963-1972 30 0.49 (0.32)a -0.14–1.12 1963-1972 28 0.56 (0.09)*b 0.38–0.74
1973-1982 30 0.27 (0.32)a -0.36–0.90 1973-1982 29 0.34 (0.09)*a 0.17–0.52
1983-1992 30 0.26 (0.32)a -0.37–0.89 1983-1992 30 0.33 (0.09)*a 0.15–0.50
1993-2002 30 0.48 (0.32)a -0.15–1.11 1993-2002 30 0.15 (0.09)a -0.02–0.33
2003-2011 27 0.27 (0.34)a -0.39–0.94 2003-2013 33 -0.11 (0.08)a -0.27–0.06
Tour 1983-1992 10 -0.14 (0.55)a -1.23–0.95 1983-1992 10 0.32 (0.15)*a 0.01–0.62
1993-2002 10 0.52 (0.55)a -0.57–1.61 1993-2002 10 0.20 (0.15)a -0.10–0.51
2003-2011 9 0.19 (0.58)a -0.96–1.34 2003-2013 10 -0.01 (0.15)a -0.29–0.28
Giro 1983-1992 10 0.40 (0.55)a -0.69–1.49 1983-1992 10 0.39 (0.15)*a 0.09–0.70
1993-2002 10 0.41 (0.55)a -0.68–1.50 1993-2002 10 0.13 (0.15)a -0.18–0.43
2003-2011 9 0.19 (0.58)a -0.97–1.33 2003-2013 10 -0.16 (0.15)a -0.45–0.13
Vuelta 1983-1992 10 0.52 (0.55)a -0.57–1.61 1983-1992 11 0.27 (0.15)a -0.04–0.57
1993-2002 10 0.50 (0.55)a -0.59–1.59 1993-2002 11 0.13 (0.15)a -0.17–0.43
2003-2011 9 0.46 (0.58)a -0.69–1.60 2003-2013 11 -0.16 (0.15)as -0.44–0.13
Notes: 1 Number of stage race wins between time periods vary due to WW I and II and the Spanish civil war. The years of the epo era are in bold type face. Predicted mean proportional changes are based regression analyses in which we used competition year, stage races, distances of the stage races, number of stages in the races, and the brutality rate of the races as predictor variables. N = 253 because proportional changes cannot be computed for the intial races. 2 The first time trial ever in professional cycling was scheduled in the 1933 Giro, followed by the Tour in 1934, and in 1941 by the Vuelta. Predicted mean proportional changes are based regression analyses in which we used competition year, stage races, and the distances of the time trials as predictor variables. We aggregated the time trials per year (N = 198).  3 Means without a common subscript differ significantly, p ≤ .05. Across stage races, we contrasted the epo period against all other periods. For separate stage races, contrasts compared the epo years to immediate adjacent time periods. To prevent Type I– errors, we adjusted the 95%–CI using the Bonferroni procedure. * Within time periods mean proportional changes differ significantly from zero, p ≤ .05.
Table 2: Descriptive Statistics of Predicted Mean Proportional Changes (%) in Winning Riders’ Km/h Performances per Time Period in Stage Races and Time Trials.