Running is built on booms. In the 1970s, the original explosion introduced people to something called jogging. In 1994, Oprah Winfrey ran the Marine Corps Marathon, spurring millions of women to flood half-marathons and other races. In 2024, the marathon boomed. The Paris Marathon in April set a record for the biggest ever with 54,175 finishers. That mark was broken not once, but twice—first in September by Berlin (54,280), then in November by New York (55,646).