The image below contains five marathon record timelines: course records for Boston (men and women) and New York (men), and world records (men and women). Each colored block marks a year where a record was set. Darker blocks in the world record timelines represent years where there were multiple record-breaking efforts.
The chart below summarizes the data.
Race courses have changed over time, and not everyone agrees on whether a particular effort was worthy of world-record status or not, so any comparisons aren’t necessarily apples-to-apples. Even so, the timelines still provide some interesting information.
The first running boom, centered around the 1970’s, shows up clearly in the data. A closer look shows that the boom started earlier, in the post-WWII years. It might be that easier travel and post-war prosperity for the middle-class created larger, stronger fields at Boston and other marathons around the world, filled with runners who set records more frequently.
In the late 60’s, women joined in the fun. Then New York became a major event (along with Chicago, Berlin, and many others). Records fell fast and furious through the mid-80’s.
The second running boom hasn’t resulted in a similar wave of marathon records. If you squint, the world record timeline might reflect the boom somewhat, but the recent timelines for Boston, New York, and women world-wide show a relative dearth of records. Maybe Color Runs aren’t much of a breeding ground for record-breaking marathon efforts?
One thing is for sure: there’s only one way I’ll ever hold a world record.