Table 3. Mean, standard deviation (time), two-way ANOVA (sex, and starting block) with Bonferroni in 50-m and 100-m individual freestyle.
  Time (s)   Block time (s)
Men (m)
(n=829)
  Women (w)
(n=827)
Men (m)
(n=829)
  Women (w)
(n=827)
Mean (SD) Mean (SD) Mean (SD) Mean (SD)
50-m freestyle
Old platform (n=509) 22.5 (.41)   25.6 (.55)   .75 (.64)   .77 (.06)
New platform (n=318) 22.1 (.47) 25.1 (.61) .68 (.44) .71 (.47)
100-m freestyle
Old platform (n=511) 49.6 (.80)   55.6 (.99)   .76 (.05)   .79 (.06)
New platform (n=318) 48.8 (.82) 54.6 (.94) .70 (.04) .73 (.05)
Whole sample by sex and starting block Sex   Starting block
Men (m)   Women (w)   Old (a)   New (b)
50-m freestyle .72 (.07) .75 (.06) .76 (.06) .69 (.05)
100-m freestyle .74 (.06) .77 (.06) .77 (.06) .72 (.05)
Main effects and interactions Sex   Starting block Sex * Starting block
F Diff. p F Diff. p F p
50-m freestyle 46.262 m<w <0.001a   291.859 a>b <0.001c .278 .598
100-m freestyle 61.412 m<w <0.001b 244.563 a>b <0.001d 1.825 .177
a: effect size=-0.46;
b: effect size=-0.50;
c: effect size=1.24;
d: effect size=0.89