How to Train for a Half Marathon in 12 Weeks

A 12-week half marathon plan gives beginners and returning runners enough time to build fitness without burning out. The best path is simple: stack easy miles first, layer in a touch of speed, then taper so you arrive fresh. Successful programs follow three phases—base, intensity, taper—and schedule 3–5 runs per week plus short strength and one cross-training day, a structure we use at Hiking Manual and echoed by widely used guides from On and Marathon Handbook (see On’s 12‑week half marathon guide and Marathon Handbook’s 12‑week plan). If you can currently run about 3 miles continuously, you can complete this program and finish confident. Below you’ll find a clear weekly structure, phase-by-phase milestones, long-run and fueling steps, Hiking Manual’s loop-first habit system, and race-week logistics to lock in a personal best with low stress.