John Walker runs 3:49.40; 43 years ago; 8/12/1975 ... The first man in history to ever break the 3:50.0..! Video in link below.
Walker may be the greatest miler of all-time ran the mile, 135x under 4:00.0...!!
His first run under 4:00.0 was on July 7th, 1973 at the age of 21 with a time of 3:58.8
Walker was the first man to reach 100 sub 4 on 2/17/85 ...! His 100th was 3:54.57 at age 33.
To become the first man to record 100x sub4 he ran ..12 sub 4 between 12/15/84 to 2/17/85..!!! ~65days/12sub-4..!
Recorded a total of 135 of sub-4; but I can't find the date of his last one... Maybe 16+ years of sub-4..!
5x sub-3:50.00...! His best 5 times sub-3:50.00...
3:49.73; 3:49.73; 3:49.50; 3:49.4; 3:49.08 ... His sixth best was 3:50.01..!
Gold medal in the 1500; the metric mile; at the 1976 Montreal Olympic Games.
http://www.teara.govt.nz/en/video/39967/john-walker-breaks-the-mile-record