Ironman triathlon: how long does it take to train for one if you’re starting from scratch?

Unfit but wondering if you can do an Ironman? Mark Kleanthous explains how long it takes to train for one safely, without putting your body at risk

Ironman South Africa

To do an Ironman safely, your body needs three years plus of endurance training, which may include marathons, long-distance cycle sportives and triathlons. This will also see you train through two winters.


Your longest phase is always base and your shortest phase is your final peaking phase. If you miss the solid, consistent block and foundation of base training, which usually takes place through winter and early spring, and concentrate more on the build phase before being sufficiently ready it could result in illness, injury or being mentally burnt out before your event.

You must keep a close check on mental burn-out, as athletes don’t like to admit they’re losing motivation. In this instance, introduce another exercise to freshen your head until you’re desperate to resume your Ironman sessions.

A 12-month plan will consist of the all-important, post-summer season three weeks of complete rest; 23-week base; 14-week building, to progress for your 10 weeks of pre-completion (peaking) work; then two weeks of tapering. Strength and conditioning exercises will be completed throughout the year. Your longest phase is always base and your shortest phase is your final peaking phase.

The icing on the cake is developing your race-pace efforts during your 10-week pre-competition stage, teaching your body to maintain ‘effort’ in the later part of each discipline and not slow down. Consistency within each stage will reward you with the performance you’re ultimately capable of.


Ironman training plans