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IRONMAN training data planning 2024

I've always been a big fan of athletes talking in detail about their training approach, thinking behind it and data. First and foremost blog wise we have the legend Lionel Sanders from whose blog I found a lot of inspiration over the years, just raw thinking of the athlete he was at that time.

Athletes develop through experiences in training, life and racing so what I write in a blog right now (09.12.2023) might no be the same thinking a year later. I hope not! Always want to upgrade and improve, although I believe through the 12+ years training in the sport I found a good blue print for what works for me and even more importantly what doesn't work!

There are so many approaches out there and even if you think you got a coach from approach A, you can be sure that the way he/she structures that actual training plan will not be the same as you thought it was going to be. The more I trained over the years, the more I understood the complextity of writing a good training plan and how experienced and good you have to actually be to get a good solid result out of an athlete.

Getting started in the sport the first 3 years I don't think I appreciated progress as I do now (having had bad racing experiences the last 2 years).

Hey, enough of the past - let's get going into what I said this blog is about:

IRONMAN Training data planning for 2024

Let's hit off with the goals that I believe are in my reach for IRONMAN Texas (27th of April 2024):


  • hold 1:17 min/100m pace nonwetsuit in fresh water (no saltwater which helps buoyancy aka faster times) resulting in around 49min. swim time total


  • Ride 320-330 watts NP for 180k


  • hold 3:55min/km pace avg. for 42.2km resulting in a 2:45 marathon time

Let's have a look what is needed rash threshold wise in order to hold those pace on paper.:


  • Threshold needed around 1:10-13min/100m long course (all I care about tbh since it related to outdoor the most, yards and short course meter times depend greatly on how feel and efficient you do the flipturns)


  • Threshold needed 410-420 watts if we calculate with a 0.79 IF (intensity factor or % of threshold) which is a common ridable intensity in order to run off of


  • Threshold needed around 3:15 min/km pace

This is just raw speed needed on paper to get the % breakdown which is one part, but IRONMAN is an 8hr event and depends greatly on your ability to burn fats and especially be very well conditioned and STRONG muscular wise to hold those pace for that duration (given calorie intake, sodium and hydration are on point and maxed out carb wise for the gut, which is another topic).

If the highest thresholds would always win, any short course athlete would smash each ironman without any issue. But now it becomes a bit more tricky.

The easiest physiological test I've heard and find pretty good and simple is:

"If someone would ask you right now to either run a 4min all out interval on the track or a 2hr long run, what would you answer?"

If the answer is 4min, you are most likely a short course guy by nature (and physiology) and if you said 2hr long run, build for long course. It's simple but works I reckon. I would have always said 2hr run even when I started the sport on shorter distances. As a kid you just know what is easier for you and more fun as well, so you choose that.

Back to the data stuff!

So once you thresholds are in the range of aiming for those paces I mentioned, I need to condition my body muscular wise and energy system wise to be able to hold the higher aerobic percentages of the threshold for the needed durations of an IRONMAN.

3800m swimming, riding 180km and running 42km.

I reckon if you struggle you struggle to hit the goal paces of any of the 3 sports on any given day, you got zero chance of achieving it on race day. Sure it'll still be challenging and requires focus and determination to execute, but let's say you blow up after 1900m in the swim and drop to 1:25min/100m pace - well you got no shot.

Same for the bike and run, if your legs give in on a hypothetical single day event of the each discipline, you won't be able to do the three in a row on race day.

Sometimes we forget that IRONMAN is called an "Endurance sport"

That has the word enduring in it and while mental focus and determination plays a key role, let's stay with data and physical ability in this blog.

In order to hold the percentages of the threshold over the full IRONMAN distance you need two things (thinking simple):



Until the race specific training phase will start 10 weeks out pre IRONMAN Texas, I will focus entirely on getting my high end in swim,bike and run as high as possible while training Z2 in all 3 sports as well.

Once we enter the race specific training phase, my training will change quite significantly in sessions with one goal in mind:

Be conditioned for the demands of the race

Let's go specific, since you nerd (yes, you!) reading this far definitely like it as much as I do, so let's get dirty here:


  • be conditioned stroke mechanic wise (in swimming 50% not actual cardio fitness) to swim very fast as take out speed for the first 5-7min ish

  • In the pool I will aim to hold 1:05min/100m pace for up to 200m in a row aka 2:10ish LCM time. What I learned from a top ironman swimmer (Andrew Horsfall) that the first 50m is actually very significant and requires a 28-29sec / 50m time, which I will also train before to get that quick turn over and power at the start

  • Holding 10x300m high aerobic pace aka 1:17/100m LCM or quicker on avg. for all 300s with only 15sec rest in between. If I can't do that fairly controlled, I can't do it on race day.

  • What I will also train once or twice (load will be quite high for that sressions don't wanne overkill either) is to train hard take out speeds and drop into race pace after, doing intervals of that like 50-150m very hard into 300m IRONMAN race pace. Just to get used to oxygen deficiency and how it feels mainly. If I feel anything discomfort wise (in smaller pockets of course) the first time in racing, I don't think I trained well for the event. In theswim psychology is huge, that's why I want to feel how that oxygen depth after hard take out feels and how long (or that at alll!) it goes aways after a few minutes of ironman pace swimming


  • be able to ride 3x1hr at 320-330 watts around 85 cadence with 10 Min. rest in between in a 4.5hr ride

  • I also got low cadence strength planned to bring down VLAmax and more importantly develop the actual strength to keep the legs turning over at race power after 120-140km/180km

  • I also plan to keep 2-4min surges at a bit over threshold in there like around 450watts ish, to remind the body that these power zones exist and will be needed on race day very likely. Ideally I would plan the short surges in the 3x1hr ironman ride but don't want to overkill either, I see how I feel in that ironman blog fatigue wise and then decide. Alternatively I will put a light high powr session in mid week (2days away from both key rides) to keep the higher power stimulated in an aerobic ride with a small set like 4x2min 450watts, 2x4min 450watts - something like that let's see.


  • key session will be a (maximum depending on fatigue of block and when I am in it) 25km run off the long 4.5hr ironman specific ride with 25km at IRONMAN race pace aka 3:55min/km

  • Key for that run is that the pace/hr ratio (hr drift) is no more than 2%. Only then I got the highest chance to do this on race day

  • Also I do a key quality long run every 2nd week to stimulate the system muscular wise and also run quicker than race pace

  • Same as on the bike, I believe if you only train at race specific paces and powers and not harder/faster (for short bouts even) even in the race specific phase, it will make you struggle on race day

Yea so that's basically the main bulk of it in simple terms.

Many of the things I mentioned I already completed before and raced very well off, but haven't done in years anymore since I was 100% comitted to the past coaches and their approaches. Lessons learned and not wasted time, but learned a lot in these periods.

I keep you posted,

Thanks for reading,


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Interesting read. If you can hit those goal numbers for IMTX you should be top 10! Awesome. Although there will probably be more big dogs there for the Pro Series. I’ll be rooting for you.

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