"How long do I need?" is one of the first questions people ask about a 70.3, and it usually gets asked with a nervous edge. What sits underneath it is: "have I left it too late?"… so let's deal with that.
If you are asking the question at all, you are taking it seriously. That matters more than whichever training plan you eventually pick.
BLUF: for most first-timers, 20 to 24 weeks is the honest answer. Not because the plan needs to be that long, but because your body needs that long to absorb the work without falling apart.
The short version, by starting point
Everyone arrives from a different place, so a single number is not much use. Here is roughly how it looks:
- Starting close to scratch (little consistent training, maybe a bit of gym or the odd run): 9 to 12 months is kind, and 6 months is the realistic minimum. Spend the first block just becoming someone who trains regularly.
- Already active, new to the distance (you run or ride a few times a week): 20 to 24 weeks works well. This is the classic first-timer runway.
- Coming back to it (you have raced before, life got in the way): 16 weeks is usually enough, as long as you rebuild the aerobic base before you touch anything hard.
- Single-sport background (a runner, or a cyclist): 20 weeks, with most of the early attention on whichever discipline scares you. Usually the swim.
Those numbers line up with how the sport generally plans it. Standard 70.3 programmes run about 20 weeks, split into a base phase, a build phase and a peak phase, and coaches consistently point to 20 to 24 weeks for anyone coming from a mostly single-sport background.
Why the runway matters more than the plan
Here is the thing most people get wrong. They go looking for the perfect plan, when what they actually need is more road between today and race day.
A longer runway does three things:
- It lets you build the aerobic base, which is where 70.3 races are genuinely won and lost.
- It gives you room to be ill, be away with work, or have a bad fortnight, without the whole thing collapsing.
- It keeps the weekly hours sensible, which is what keeps you married and employed.
So, what that means is: if you have 30 weeks, use 30 weeks. Do not compress a 24-week plan into 12 and hope. That is how people get injured in week 9 and never make the start line.
What a week actually looks like
A typical first-timer week has two swims, three bikes and three runs, with one long ride and one long run, plus a bit of strength work. At peak that is around 8 to 10 sessions and roughly 8 to 10 hours.
That being said, plenty of people get to the line on less. Research following first-time half-iron athletes found an average training volume of about 410 minutes a week, which produced an average finish of around 6 hours 28 minutes. That is under 7 hours of training a week.
The key takeaway is: consistency at 6 hours beats heroics at 12 followed by three weeks off. Better to be consistently good, than sporadically great.
The bit people underestimate
Not the distance. The life admin.
Kit that fits, a bike that has been serviced, an open water swim or two before race day, a nutrition plan you have actually rehearsed, knowing how transition works. None of that is fitness, but all of it takes time, and it is what turns a nervous first-timer into someone who looks like they belong there.
Try this: build those into the plan from week one, not race week. One open water swim a month from spring onwards does more for your nerves than any session.
How to work out your own answer
Here is what to do:
- Be honest about today. How many hours a week have you genuinely trained, on average, over the last three months? Not your best week. Your average.
- Pick the race that fits the runway, rather than picking a date and panicking backwards from it. Our race guides show you the course, the terrain and what the day actually asks of you.
- Check the maths. Put your current numbers into the pacing calculator on any race page. It will show you a predicted finish and your cut-off margins, which tells you very quickly whether you have enough time to prepare properly.
- Add a buffer. Whatever you plan, assume you will lose two weeks somewhere. Life happens.
The bottom line
20 to 24 weeks is the honest answer for most people coming to a 70.3 for the first time, and closer to 6 to 12 months if you are starting from a standing start.
But the number is not really the point. The point is starting the aerobic work early, protecting your consistency, and giving yourself enough road that a bad week is just a bad week.
You don't have to have a great start, but you do have to start, to be great.
If you have any questions, queries or concerns about picking your race or your runway, don't sit on them, let me know.