16 Week Winter Running Plan Base phase: 6 weeks Aerobic Development phase: 6 weeks Race-Specific Introduction phase: 4 weeks Base phase builds from 5 miles per week to 15 miles per week. Aerobic development maintains around 15 miles per week. Race-Specific Introduction phase maintains at 15 miles per week. Down weeks built into training schedule. This plan is built for a newer high school runner looking to prepare themselves for the upcoming spring track season. This runner is looking to ...