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The TBN #36-Marathon Before Ironman: Is It Worth It? No. But If You Want to Run One and Get a PB, Here's How.

Updated: Apr 8

Read time: 3min.

By Coach Yan Busset

It’s Useless to Test Yourself in a Marathon Before an Ironman

But as a Triathlete, If You Want to Run One and Get a PB, Here's How:

If the thought of racing a full distance triathlon is in your mind, and you've never done a triathlon before, I wouldn’t recommend jumping straight into an Ironman for your first race. It makes sense to work on your triathlon ABC over shorter distances first. This way, you can acclimate to race elements like the swim start, transitions, and running off the bike. In short distances, you can overcome small mistakes and learn from them, but in a full distance, small errors can end your race.

At some point in your preparation, you might wonder if it’s wise to run a marathon (if you haven't done one before) before your Ironman to gauge what it takes. Counterintuitively, I wouldn’t recommend it. Why? Primarily because a standalone marathon is not like running one after “warming up” with a 3.8km swim and a 180km ride. The feeling and pacing will be very different. You won’t get an accurate picture of what an Ironman marathon demands, potentially leading to misguided pacing strategies for the actual full Ironman race.

Photo credit: @runningforendorphins_ @tuomopilvijarvi

Secondly, I advise against racing a marathon during your full Ironman prep because if you aim to do well, it requires blocks of specific training for weeks before and weeks of recovery afterward. This means deviating from your ideal full Ironman preparation for a long time. Instead, increase your overall volume with longer and more frequent swim, bike, and run endurance sessions. It’s perfectly fine to run your first marathon during your full Ironman.

That said, running a solo marathon for the first time or aiming to improve your PB in the distance is an very cool goal. I recommend leveraging your full-distance summer preparation to build robust fitness and targeting a marathon race date towards the season's end. After recovering from your full Ironman, you can then dedicate yourself to specific marathon preparation without interfering with your triathlon season. A 6-8 weeks focused training give great results, for someone already in Iron-fit,  if you’ve been consistent throughout the season.

In your marathon training, use your multisport background to your advantage. Continue cycling to build endurance, which has less impact on the body, so you can focus on quality running sessions rather than excessive run volume, reducing the risk of injury. Also, 1-2 short swim sessions per week will be a great "body maintenance tool" and help keep the doctor away. Swimming provides an excellent full-body, gravity-free stretch that can fix minor joint pains.

Regarding your long runs, limit their length to 2-2.5 hours max. The duration should depend on whether you are a heavier, more muscular athlete or a lighter one, as stride impact and recovery will be longer the more strong built you are. An alternative to the single long run, is to split it into two runs in a day. This approach ensures better running form, again reducing the risk of injuries which often comes from poor form.

Generally, it’s better to spread your run sessions throughout the week rather than packing them all into the weekend. While there's no one-size-fits-all program, a weekly routine of 1 swim, 2 bike sessions (one Z2 and one hill reps), 2 strength sessions, and 6 runs (1 long run, 1 tempo/hill reps, 1 track/interval, and 3 shorter shuffle/endurance supportive runs) should set you up to nail your personal best! Keep in mind this example is for someone that just when thought a full distance preparation. not for someone, that start from zero.

So remember: There’s no need to run a marathon before your full Ironman; the insights gained won’t be particularly useful. And if you’re aiming for a great marathon, plan it for the end of the season, using your Ironman preparation and triathlete background as your strengths.

Looking for More Tips?

Check out some of my past articles that are in connection with this article:

Thank you for reading and see you next week!


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