Start training for your next long-distance triathlon with this free 6-month Ironman training plan

Completing a base training plan for Ironman is crucial to laying down the foundations for the season ahead. It’ll also ensure your body is in the best shape possible when you start the intensive training phase.

The volume of this free six-month Ironman base training plan is fairly light at the start. But it’ll build progressively at a rate that allows you to stay injury-free and motivated to keep developing base fitness.

There’s a difference between base fitness and base strength, we so recommend looking at our free eight-week strength building training plan too.

Most of the sessions in this Ironman preparation plan are aerobic. This is perfect for promoting the kind of energy systems that are used predominantly in long-course triathlon racing.

If you don’t have time for six months of base training, you could follow our free three-month Ironman base training plan instead.

What to focus on during Ironman base training

Base training isn’t about speed or race simulations. Instead, the goal is to build foundational fitness, perfect technique, and maintain training consistency across all three disciplines.

During this six-month period, athletes should prioritise developing aerobic endurance at lower intensities, refining technique in the swim, and improving cycling economy. Running volume should increase gradually, with a focus on good form and injury prevention rather than pace.

This phase is also the ideal time to establish sustainable training habits. Learning how your body responds to higher frequency sessions, early mornings and back-to-back workouts will pay dividends later when training intensifies.

Resist the temptation to push too hard too soon. A successful base phase leaves you feeling stronger and fresher, not burnt out.

Recovery, nutrition and consistency in the base phase

Although the training intensity is relatively low, recovery remains a key part of Ironman base training. Regular sleep, easy days and lighter recovery ‘deload’ weeks are essential for absorbing the work you’re putting in.

Nutrition should support steady training rather than weight loss or aggressive fuelling strategies. Focus on eating well around sessions, staying hydrated, and practising simple fuelling during longer rides and runs. This helps prepare your gut for the demands of Ironman training later in the season.

Most importantly, consistency matters more than any single workout. Missing an occasional session isn’t a problem, but regularly overreaching can derail your progress. Aim to string together solid weeks of training and arrive at the next phase healthy, motivated and ready to build.

Coach Dermott’s Ironman base training plan tips

1. Keep training routes simple

The terrain doesn’t need to be too technical or challenging: just get out there and get moving.

2. Under control

For all athletes, complete bike interval sessions in a location that allows you to control the environment. This means they’re often best conducted indoors on a turbo trainer.

All pool sessions are based around a 25m pool but adjust accordingly.

3. Personalise the plan

And, of course, adapt these plans to your own tri strengths and weaknesses.

Sign up for the six month Ironman base training plan here:

Once completed you’ll be the perfect place to begin your intensive IM training, and in particular our six-month Ironman training plan. If you’re very well organised and have more time ahead of the big day, you can use our free 12-month Ironman training plan.

But don’t worry if time is tighter. Our free 3 month Ironman training plan will help you capitalise on the time available.

For more long-course advice, don’t miss our 30 Ironman training and preparation tips and happy training!