Is This Plan For You?
This 18-week Intermediate Marathon plan by GA Endurance is designed for runners with a strong training background who are ready to prepare for a marathon within a condensed, performance-focused timeline.
It is ideal for athletes with a well-established aerobic base who want to transition immediately into structured, race-specific training and maximize performance through efficient and disciplined execution.
If you are looking for a direct, highly focused approach to marathon preparation with minimal base work and a strong emphasis on race readiness, this plan provides a clear, structured pathway.
What You Can Expect
• A complete 18-week structured Marathon progression leading into race day
• Very limited base phase with immediate transition into build and race-specific training
• Strong emphasis on aerobic efficiency, durability, and fatigue resistance
• Progressive long runs designed to rapidly develop marathon-specific endurance
• Early and frequent tempo, threshold, and race-pace sessions
• Strategically placed recovery weeks to support adaptation and manage fatigue
• High focus on pacing precision, efficiency, and energy management
• Clear, easy-to-follow workouts using pace, heart rate, or perceived effort
• Optional strength guidance to support durability and movement quality
• A performance-driven structure built for efficient marathon preparation
Coaching & Support
This plan includes Coach Access.
If you have any questions during your training, you can reach out anytime via:
coachsupport@gaendurance.com
Requirements
To start this plan, you should be able to:
• Run continuously for at least 18–22 km
• Train consistently 4–5 times per week
• Have a strong aerobic base and recent structured training experience
• Be ready to handle a high-quality, performance-focused marathon progression
A GPS watch and heart rate monitor are recommended for best results.
Final Note
This 18-week intermediate marathon plan is built for athletes who are already prepared and want to maximize performance within a shorter preparation window.
With almost no traditional base phase, the emphasis is placed on execution quality, consistency, and race-specific adaptation. If followed with discipline, this plan will help you build endurance, refine pacing strategy, and arrive at race day confident and ready to perform.
Explore more training plans at GA Endurance
Goksen Cinar, MSc, is a sports scientist, national team coach, and founder of GA Endurance. With more than 25 years of coaching experience, he combines sports science, endurance coaching, and data-driven methodology to help athletes achieve sustainable performance improvements. He is a 4-time Ironman 70.3 World Championship qualifier and 4-time full-distance Ironman finisher.