How to improve your Ironman run

The marathon times in Ironman over the last few seasons have started to get seriously quick. It isn’t abnormal for Pros to run sub 2.40 which is an impressive time by itself. The most notable time being Gustav Iden’s recent 2.34 marathon at IM Florida, an incredible 3.41min/km average. However, while many are running fast times, a lot are still faltering in this part of the race and many age group athletes can’t back up a good swim and bike.

While I haven’t run anything like as fast as Gustav, I’ve gone under 3 hours in my last two IMs and have always been able to rely on a solid marathon leg to pull me through the field and ultimately get a Kona slot. I’ve always had the mantra that an IM starts at 30km into the marathon. Going sub 2.40 in an IM takes a certain level of talent but running a solid marathon and getting close to 3 hours or going under isn’t that hard if you do the right training.

I’ve always had the mantra that an IM starts at 30km into the marathon.

Most athletes can go out and run at the pace they want to run at in an IM in training, they just can’t run at that pace easily enough to hold it in a race for 42km. There’s a key difference between trying to get faster, and then trying to make yourself more economical at IM pace so you can sustain that desired intensity. Of course, you need to do some speed work but you have to optimise your efficiency. I thought I would share how I structure my run training in the build-up to an IM. Two athletes could do very similar run training but achieve very different marathon results based on how they manipulate the variables that surround the training.

How to structure your week:

·      Ideally do a long IM intensity bike with a short run off the bike at above IM pace. This is great preparation for race day and reduces the chances of injury as doing a long run off the bike causes a lot of stress;

·      and then, ideally the day after (can be two days later but not as effective), do your long IM run. This pace shouldn’t be too fast but your legs will be tired and this makes it tough. By running on tired legs, you’ll make your training specific to the demands of the event and develop the ability to run well under high levels of fatigue;

·      everyone can train well when they feel great but you won’t feel great when you get off the bike in an IM. This style of training builds your mental resilience as well as your fitness; and

·      make sure and build in recovery time after this training. This type of load puts a massive stress on the system and you have to get your feet up and then do some low aerobic training the following day/s.

What intensity should you go at:

·      As above, your run off the bike should be faster than IM pace, this can be broken down into intervals as well. You could do 1min fast/1min easy or something like 5x1km at 70.3 pace with 1min recovery; and

·      your long run should build in intensity as you go through the run. Remember, we’re trying to develop strength in the legs and an IM gets hardest in the later stages so we want to develop our ability to keep pushing at the end of a run. Doing an hour at IM pace and then dropping your pace by 10-15secs per km for the following hour is a fantastic way to develop the ability to actually run at target IM pace.

How far should you run:

·      Your run off the long bike could range from 5km to 10/12km but running too much further than that isn’t necessary;

·      over the course of your IM build, your long run the next day should increase in distance so that you’re running a broken marathon over the 2 days by the end of the build. Eg if your brick run is 8km you could then run 34km the next day; and

·      athletes trying to run very quick times could benefit from going slightly longer than this and doing up to 37/38km as the long run.

How should you fuel the long run?

·      As we’re trying to develop efficiency, we want to improve the ability to metabolise fat at race pace. This is one of the most critical factors in IM performance and is the reason many athletes simply can’t sustain the pace then want to - they can’t take on enough carbohydrate to fuel the pace and they aren’t efficient enough at using fat as a fuel source;

·      you should ideally have nothing to eat before the long run or have a higher fat meal like eggs or bulletproof coffee if you’re hungry. This will prime your body to metabolise fat and spare muscle glycogen;

·      consuming some caffeine may help your fat metabolism;

·      as you get further into the IM build and the long runs start to get longer, you should start adding your race nutrition into it in the later stages so you can train the gut to absorb the carbohydrate;

·      I will typically do the first 60-90minutes with no exogenous carbs and then I’ll start taking my race nutrition for an hour so my gut gets comfortable with absorbing that;

·      and make sure and refuel well after the long run so the recovery process can start.

Conclusion:

The takeaways are focus on building strength in the legs by running on the right days and at the right pace, build your volume in a controlled way so you’re ready to run the distance and fuel your training in a way that promotes metabolic plasticity. You simply can’t run a good IM marathon if you don’t develop your ability to metabolise fat at race intensity. Looking at all these different aspects and putting them together will develop your ability to run at your goal pace and put together a complete race.

One factor we’ve not talked about is preparing for different environment conditions, like hot weather, but we’ll cover that in another article. Hope this helps you think about what you should and shouldn’t be doing the next time you’re building towards an IM. Comment below if you have any questions.