Is This Plan For You?
This 20-week Marathon Base plan by GA Endurance is designed for runners who want to build a strong, durable, and high-capacity aerobic foundation before progressing into race-specific marathon training.
It is ideal for athletes who are either returning to structured training or aiming to develop long-term endurance, consistency, and resilience required for advanced marathon performance.
If your goal is to establish a deep aerobic base, improve efficiency, and prepare your body for high-volume and race-specific workloads, this plan provides a clear and progressive pathway.
What You Can Expect
• A complete 20-week structured Base progression
• Gradual and controlled volume increase to support long-term adaptation
• Strong emphasis on aerobic capacity, efficiency, and movement economy
• Consistent, easy, and steady-state runs to build endurance durability
• Introduction of controlled tempo work to prepare for future intensity
• Progressive long runs to extend aerobic capacity safely
• Periodized recovery weeks to support adaptation and reduce injury risk
• Development of structural durability (tendons, muscles, connective tissue)
• Clear, easy-to-follow workouts using pace, heart rate, or perceived effort
• Optional strength guidance to support injury prevention and durability
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 8–12 km
• Train consistently 4–5 times per week
• Be ready to follow a progressive endurance-focused structure
A GPS watch and heart rate monitor are recommended for best results.
Final Note
This 20-week base plan is designed to build the physiological and structural foundation required for high-level marathon performance.
You will develop aerobic capacity, improve durability, and establish the consistency needed to successfully transition into advanced marathon training.
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.