An Ironman 70.3 is a 1.9km swim, a 90km bike, and a 21.1km run, one after the other – also known as a Half Ironman.The distance is demanding but the training that prepares you for it is less about any single big session and more about putting together weeks of consistent work across three sports. Choosing a half ironman training plan training plan that fits your life is what keeps that consistency possible.
Most plans fail not because the sessions are wrong, but because they were built for a week you do not have. Before you look at any plan, it helps to be honest with yourself about three things: how much time you can genuinely give each week, where your fitness is now, and what you actually want from race day. For more information, read our guide on what an Ironman 70.3 training block really involves.
Start with the hours you can genuinely protect
A triathlon block asks for training across swimming, cycling, and running, and those hours have to come from somewhere. The first question is not how many hours a plan recommends, but how many hours you can protect, week after week, around work, family, and everything else that fills your days.
Work out your realistic number, not your optimistic one. If your calmest week allows around six hours and your busiest allows four, build from four, not from the six you hope to find. A plan built for ten hours will land too heavily on a schedule that only holds six, and the shortfall tends to show up in the first genuinely hard week.
It also helps to think about when those hours sit. A plan that assumes you can train early every morning will not work if your mornings are already taken. Look for a plan whose rhythm matches the shape of your week, not just its total.
Be realistic about where your fitness is now
Your starting point matters as much as your schedule. Someone coming from regular running and cycling will handle a build differently from someone who swims once a fortnight and has not cycled far in a year. The honest version of your current fitness is the most sensible place to begin, even if you intend to build well beyond it.
Swimming is often the deciding factor. If open water is new to you, you will need time in the water early, not a plan that assumes you can already cover the distance comfortably. If one of the three sports is much weaker than the others, a plan that treats all three equally will leave that gap unaddressed.
If you are returning from injury, illness, or a long break, the gentler starting point is the right one. Building back up takes patience, and a plan that assumes the fitness you had last year rather than the fitness you have now will usually ask for too much too soon. Always consult a medical professional when you take on structured training, including after injury or illness.
Match the plan to what you actually want from race day
“Train for a 70.3” can mean many different things. For many first-timers, the goal is to finish feeling strong and to enjoy the day. For others, it is a specific time. Different goals shape a plan differently, and a plan built for one will not serve the other well.
If finishing is the goal, the priority is steady endurance and getting comfortable moving from one sport to the next, particularly off the bike and onto the run. If a time goal matters to you, the plan will include more structured harder work, but that work only helps once the endurance base is there. Chasing a time before you have built the base tends to leave you tired rather than faster.
Be honest about your goal for this race. There is no wrong answer, but choosing one keeps your training pointed in a single direction.
How long a build you need
The right length of plan depends on how far your current fitness sits from the start line. Someone already training regularly across the three sports may need a shorter build than someone starting from a lower base. A longer runway gives you more room to absorb a missed week or a bad patch without the whole plan unravelling.
A longer plan is not automatically better. What matters is whether the weeks give you enough time to build gradually. If the increases feel manageable and you are gradually getting stronger rather than steadily more worn down, the length is working. If you are consistently tired week after week, consider whether the build has gone up too fast.
Signs a plan is wrong for you
Missing sessions repeatedly is not a discipline problem. It usually means the plan was built for a different life than the one you have. That is not a failure, just a misalignment, and the solution is to work out what you can actually do, rather than get down on yourself for not meeting the expectations of this plan.
A few other things are worth watching for. A plan that has you training at one effort all the time is not likely to give you the result you are looking for, because easy work and harder work do different jobs. A plan that keeps the pressure on right up to race day is not setting you up for success, since you need an easier stretch before the race to arrive fresh. A plan that ignores your recurring commitments, the Tuesday club swim or the weekend you always give to family, is a plan you will constantly be fighting.
Build in room for the weeks that go sideways
No training block survives contact with a real year untouched. Work runs over, children get ill, a cold knocks you back for a week. The best plan for you is one you can adjust without feeling you have ruined it.
When a hard week hits, the aim is to protect the habit rather than complete every session as written. Dropping or easing a session and protecting your sleep usually keeps the rest of the week intact. A plan you can bend around a difficult patch will outlast one that demands perfection and then leaves you feeling you let it down when really, the opposite is true. The plan did not account for your life.
Pay attention to how training feels over time, not just whether you ticked every box. Poor sleep, rising fatigue, and sessions that feel harder than they should are signals that something needs to ease. Listening to those signals is part of training well, not a sign you are falling behind. If you notice pain that is sharp, that gets worse as you train, or that lingers afterwards, stop and see a physio or GP rather than training through it.
Putting it together
Choosing a 70.3 plan comes down to matching three things: the hours you can realistically protect, the fitness you genuinely have now, and the goal you actually care about for race day. A plan that fits all three is one you can stick to, and sticking to it is what gets you to the start line prepared.
Revay builds a personalised triathlon plan around your schedule, your current fitness, and your goal, and adapts it when your body or your week changes, with every adjustment proposed to you rather than imposed. If that sounds useful, sign up for more information about the beta below and we will let you know when it is ready. Say hello any time at hello@revay.app.