Uh, is this a real question.
Endurance sports are traditionally dirty as hell.
Lets go through the endurance track and field world records and identify ones considered very likely "dirty"
Womens:
800m: Jarmila (common knowledge was doped to the gills)
1500M: Dbiba (coach arrested for doping)
3000m: Jungxia (common knowledge was doped to the gills)
5000M/10,000M: Gidey (no evidence, but times are suspicious)
Mens:
800m: Rudisha (no evidence)
1500m: El Guerrouj (basically was a chemical experiment, no testing in a third world country, peak EPO era)
3000m: Komen (same as El Guerrouj)
5000m/10000m: Cheptegei (no evidence, but suspicious)
Of the 8 world records, 5 are either common knowledge/all but confirmed dopers.
Yet Kipchoge, running the ULTIMATE endurance event (the marathon), with one of the most ridiculous WRs relative to the field shouldn't be suspicious? LOL. He's suspicious as hell due to the company he is associated with (WR holding distance runners).