Quad Dipsea

Quad Dipsea is run in Mill Valley, California, on November 28, 2026, over a single 28.4-mile trail course starting at 7:30 AM. The name describes the format: four passes along the Dipsea Trail between Mill Valley and the coast, run out and back twice, which means every climb is also a descent later in the day and every descent comes back as a climb.

This is a stair-heavy, quad-destroying kind of race rather than a fast one, and finishing times spread far wider than the distance would suggest. Treat it as a hard 50K rather than as a marathon plus four miles. Downhill training is the single most useful thing you can do in the last two months: repeated long descents at controlled effort, so your legs still absorb the fourth crossing the way they handled the first.