12 Week Intermediate Full Distance Base Phase Training Plan - 2026

This plan is for athletes who want to build the engine first before moving into a full race-specific long-course block. It works well if your race is still further away, or if you know you need a stronger aerobic base before the bigger weeks begin. It is written in the way we coach at TCC Endurance: practical, progressive, honest, and built around consistent training rather than chasing one-off hero sessions.

Across the 12 weeks you will focus on consistent aerobic work, good habits, and controlled progression across swim, bike and run. The weekly volume sits around 8-15 hours, so it is aimed at athletes who can train regularly while still keeping recovery and real life in the picture.

Who this plan is for

• Athletes preparing to start a stronger full distance / 140.6 build.


• Athletes who have completed shorter triathlons, middle distance events, or already have a good endurance background.


• People who want structure, progression and clear guidance rather than a random collection of sessions.


• Athletes who can train most weeks between 8-15 hours.

What to expect

The plan includes structured swim, bike and run sessions with a clear purpose behind the work. The aim is to build fitness you can actually use later in the season: better endurance, better control, and more confidence before the race-specific training starts.

The aim is not to make training more complicated than it needs to be. The aim is to help you arrive at race day fit, prepared, confident, and with a good understanding of how to pace and manage the distance.

TCC coaching approach

At TCC Endurance we believe the best long-course results come from consistency, smart progression and knowing when to push and when to absorb the work. This plan reflects that. There are challenging weeks, but the training is there for a reason, and the easier days are just as important as the harder ones.

If you follow the plan well, listen to your body, and keep the bigger picture in mind, you will give yourself a strong platform for a successful full distance race.

Included in the plan

• 12 weeks of structured full distance base training.


• Swim, bike, run and supporting endurance sessions.


• Progressive weekly structure leading into race-specific preparation.


• Clear session guidance so you know what each workout is trying to achieve.


• A taper into race day so you arrive fresh and ready, not flattened by the training.

This plan has been reviewed and updated for the 2026 season.

If you are not sure whether this is the right plan for you, or you have any questions before getting started, email info@tccendurance.com and we will point you in the right direction.