Is This Plan For You?
This 12-week Half Distance Intermediate Base plan by GA Endurance is designed as a structured foundation phase for athletes preparing to enter a race-focused training block.
It is ideal for triathletes who already have a consistent training background and want to further develop aerobic capacity, durability, and training consistency before progressing into higher intensity and race-specific work.
If you are looking to build a strong and sustainable performance base that supports long-term development and future race execution, this plan provides a clear and structured pathway.
What You Can Expect
• A complete 12-week structured Base progression for Half Distance Intermediate athletes
• Moderate and progressively increasing training load
• Strong emphasis on aerobic development and endurance capacity
• Balanced progression across swim, bike, and run disciplines
• Progressive long sessions to build durability and fatigue resistance
• Limited but structured introduction of tempo and sub-threshold work
• Bike sessions focused on steady power output and efficiency
• Run sessions designed to improve aerobic strength and movement economy
• Swim sessions including technique refinement and aerobic conditioning
• Controlled brick sessions to maintain neuromuscular adaptation
• Strategically placed recovery weeks to support adaptation and prevent overload
• Clear, easy-to-follow workouts using power, pace, heart rate, or perceived effort
• Optional strength guidance to support durability and injury prevention
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:
• Swim at least 1,500–2,500 meters continuously
• Ride consistently for 2–3 hours
• Run continuously for 60–75 minutes
• Train consistently 4–6 days per week
• Have prior experience with structured triathlon training
A GPS watch, heart rate monitor, and bike power meter are recommended for best results.
Final Note
This 12-week intermediate base plan is designed to build a strong and sustainable aerobic foundation before entering a race-specific training phase.
With a focus on consistency, controlled progression, and durability, this block prepares your body for higher intensity and more demanding workloads. If followed with discipline, you will transition into your next training phase stronger, more efficient, 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.