This document outlines Meg and Fin's 18-week marathon training plan, which gradually increases their long run distances from 6 to 20 miles. On Mondays and Fridays they rest, and do cross-training on Sundays. Their runs are 3 miles on Tuesdays and Wednesdays initially, increasing over time. Saturdays are dedicated to their weekly long run, starting at 6 miles and building up. The plan provides structure and progression to prepare them for their marathon in 18 weeks.