Dan Larson, a Yale grad and longtime family physician in
upstate NY, ran his first marathon at age 17--the Holyoke (MA) Marathon of June, 1969. He finished in 3:32.
The next April, at age 18 in 1970, Larson finished his first Boston Marathon in 2:53:22. Larson finished the 2022 Boston, at age 70, in 4:36:47.
Between 1970 and 2022, he missed only one Boston. He is believed to have the fastest average time among the few who have finished 50 or more Boston Marathons.