Well, consider that the first modern Olympic games were held in 1896, and Bannister didn't set his mark until 1954. There would have been no issues with time/d

Well, consider that the first modern Olympic games were held in 1896, and Bannister didn't set his mark until 1954. There would have been no issues with time/distance measurement accuracy during that period and yet no one did it. But, as soon as he did, tons of people started doing it. And it's not like they didn't have amphetamines back then, either. So it doesn't sound implausible to me that Bannister really was the first.