You've caught the triathlon bug. You've watched the finish line videos, read the race reports, and somewhere in the back of your mind a voice is saying: I want to do that. Now comes the question almost every aspiring long-course triathlete faces — do you start with a 70.3, or go straight for the full IRONMAN?
It's a more personal decision than most people realise. Here's what you need to know to make the right call.
What's the Actual Difference?
An IRONMAN 70.3 — also called a Half IRONMAN — consists of a 1.2-mile swim, 56-mile bike, and 13.1-mile run. A full IRONMAN doubles everything: 2.4-mile swim, 112-mile bike, and a full 26.2-mile marathon.
On paper, that sounds like double the challenge. In practice, the jump is significantly bigger than that. The training volume, race-day nutrition demands, pacing complexity, and mental load of a full IRONMAN are in a different category entirely — not just longer, but fundamentally harder to execute well.
The Case for Starting With a 70.3
For the majority of first-time long-course triathletes, a 70.3 is the smarter entry point — and here's why.
It teaches you to race triathlon. Open-water swimming in a mass start, transitioning between disciplines, managing pace on the bike so your legs work on the run — these are skills that take practice. A 70.3 lets you learn them at a distance that's challenging but forgiving.
The training is more manageable. Peak training weeks for a 70.3 typically sit in the 8–10 hour range. For a full IRONMAN, you're looking at 10–15 hours. For athletes with full-time jobs and family commitments, that difference is significant.
Race-day nutrition is simpler. Fuelling for 4–6 hours is a very different challenge to fuelling for 10–17 hours. Gut issues are one of the most common reasons athletes have a miserable IRONMAN experience — practising nutrition at the 70.3 distance first dramatically reduces that risk.
You'll enjoy it more. Arriving at your first long-course finish line feeling strong and in control is an experience worth protecting. Many athletes who jump straight to a full IRONMAN survive it — but don't enjoy it. A 70.3 first gives you confidence, not just a medal.
When Going Straight to Full IRONMAN Makes Sense
That said, skipping the 70.3 isn't always the wrong move. If you have a strong endurance background — years of running, cycling, or swimming — you may have the base fitness to handle full IRONMAN training without the stepping stone. Some athletes also simply feel more motivated by the bigger goal, and motivation is a genuine training asset.
The key is honest self-assessment, not ego.
The Verdict
Start with a 70.3 if you're new to triathlon or long-course racing. It will make you a better athlete, a smarter racer, and significantly increase your chances of having a full IRONMAN experience you actually want to repeat.
Think of it less as a compromise and more as the beginning of a longer journey — because for most triathletes, that's exactly what it becomes.
Coach Ross