If you’re an intermediate or competitive swimmer, or a triathlete looking to improve your swim performance, Project Sub-6 is a focused 4-week training block designed to help bring your 400m swim time down towards the 6-minute barrier.

Rather than simply adding more volume, this plan uses structured, purposeful sessions to improve the specific fitness needed to swim a faster, stronger, and more efficient 400m.

Who Is This Plan For?
This plan is aimed at intermediate and competitive swimmers, as well as performance-focused triathletes, who already have a solid swim base and want a clear, targeted block of training to improve their 400m performance.

You should already be comfortable swimming regularly, handling structured sessions, and swimming approximately 6:30 for 400m.

What Does The Plan Focus On?
Across the 4 weeks, the training is designed to improve:
🔹 Threshold swim speed
🔹 Race pace familiarity
🔹 Aerobic endurance
🔹 Speed endurance under fatigue

The goal is not simply to swim harder, but to sustain a strong race-relevant pace with good technique as fatigue builds.

What’s Included?
The plan combines structured interval sessions, race pace work, aerobic support sets, and controlled speed endurance training to progressively improve both swim fitness and pacing confidence.

Training builds steadily across the block, helping you become sharper, fitter, and more efficient over 400m.

The Bigger Picture
The aim of this plan is simple: to help you attack the 400m with greater confidence and move yourself closer towards that sub-6 benchmark. ✅