16 weeks for first Full Ironman

Need advice for tackling my first Ironman coming up in a quick 16 weeks. I’m debating between doing a mixture of the three phases but unsure which ones to prioritize, or to do a 4/4/8 or 4/8/4 or 0/8/8. Any thoughts on this?

I’m in decent physical shape for swim and run so not too worried about those. Been biking some, maybe 2/3 rides a week but none longer than an hour. This will be my first Ironman (have done a half) and first time following a training plan

Working your way through Base and Build is the usual advice is this situation, and especially so if you are only currently riding for an hour. Get the bread and butter of those phases done and you’ll give yourself the best chance of success in your race.

Good luck!


I’d be practicing swimming if I were you…

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I would encourage you to stop and think.

The best approach is to plan and start training for your first Ironman a year or two in advance. This is not a fun run we’re talking about here.

Swim and bike like your life depends on it.

This is gonna hurt!

Sorry I didn’t explain the swim and running shape I’m in. Collegiate swimmer, I usually just try and relax during the swim and let me years of technique carry me without expending too much energy. And I have been consistently running the past year/two

Sounds like you’re fine on the swim being a former college swimmer.
Bike…uh that’s where you’re in trouble. You need to start riding 4-5 times a week. Coming from someone who’s done an Ironman, it’s all about the bike. Super long and have to come off fresh enough to finish for the day. 3 rides for 60-90 min during the week minimum, and get a long ride in on the weekends, starting a 3 hours and go up from there. Include some of the sweet spot rides in there.
Run, with your bike fitness this is going to include a lot of walking. Your legs are going to be fried within 10 miles. All run training should just be east run pace. Don’t waste time/recovery doing fast work like tempo/400 repeats/even half marathon pace. How fast you’re going to run in this Ironman is going to be so much slower than what you would run for a marathon.
Ultimately I think the best thing you can do is trying to make the day and enjoyable as possible and not be a death march. Good luck and let us know how it goes!


Being a good swimmer is a great start. :+1:

What have been your weekly swim and run volumes for the last six months?

16 weeks is plenty of time to train for an ironman for an ex-collegiate swimmer. If you are in good shape now, and really have been riding 2/3 times a week for some time, you will be able to build to an IM in 16 weeks. Don’t let others worry you. I would start the base plan and do the first couple weeks of the build before moving into a taper. I would probably replace the weekend long ride with an outdoor long ride building to race distance. Getting a couple 112 mile rides in before race day will go a long way in building confidence and practicing your pacing/nutrition strategy.

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