More than 27,000 runners are expected to descend upon Los Angeles for the 2026 LA Marathon​ on Sunday, running more than two dozen miles across the city and creating a long list of road and freeway closures.

If you have some shorter races under your belt but this is your first half marathon or you’re new to running in general, a plan focused on minimum mileage should build up to about 15 to 25 miles per week.

Running 26.2 miles sounds ambitious at any age, so it’s surprising how often people in their late 80s, 90s, and even past 100 have crossed marathon finish lines. Big city races with open entry rules helped make many of these moments possible.