Free 3 month Ironman base training plan

Got designs on conquering Ironman? Then don't neglect your base says Dermott Hayes. Here's his 3-month IM base training plan to follow

Free 3 month Ironman base training plan

Is this the year you will tackle the beast of Ironman? Then make sure you give yourself plenty of time to build up – the longer, the better. And starting with a structured and progressive base-phase plan is the way to prepare for success. It’s arguably the most important part of your Ironman journey – the need for laying down strong physiological building blocks is essential. 


The base phase may seem boring to some, but with enough base preparation, you’re less likely to crumble. A long base phase helps to prevent injury and reduce the chances of fatigue. Critically, this is the time when you can train your body to burn the most amount of fat for energy and become metabolically efficient.

To take on the challenge of Ironman, ideally you will have already completed the Olympic or half-Ironman distance and have an understanding of the discipline needed for long-distance triathlon. As a minimum, we suggest that you’re physically capable of completing a 2km swim, an 80-90km bike and a 15km run on their own.

As the main objective of the base phase of this plan is to build endurance at lower-to-moderate intensity, the bulk of the weekly sessions are completed at a Rate of Perceived Exertion (RPE) of between 5-7 out of 10. This level of intensity allows you to concentrate on form and efficiency. To help with setting training targets, we get you to complete tests in weeks one and two, before repeating them in weeks 11 and 12. The plan begins at five days per week which, once established, increases to six days. The training sessions are progressive, both in their duration and their intensity, at a rate that allows you to feel that the steps are achievable. You can expect the volume of training to increase by no more than 10% every two or three weeks.

Without becoming obsessed by numbers, keep an eye on key stats, such as heart rate, power and pace. In particular, look at the data from your tests in each discipline. Don’t worry too much about becoming faster during the base phase. Instead, focus on becoming more efficient; a lower average heart rate over a set distance or time is a great sign of physiological improvement.

3 top tips


A solid base is not created in just a few weeks. It takes time to see results.


Efficiency and form are as important as fitness. Now is the time to get the basics correct.


Organise your training into your lifestyle. Missed training sessions are lost opportunities.


Make notes on your performance, feelings and weight. Create a diary of your progress.

Download the Free 3 month Ironman base training plan below