Bike to Ironman – A guide for Cyclists want to complete and Ironman Triathlon

Ironman Competitir at Kona HawaiiThe Bike leg is, on average, the longest section of an Ironman. Obviously by distance, but it is also where most people spend the most time. Successful and enjoyable Ironman performances are forged on the bike. Over cook a Bike leg and you can almost guarantee a long painful marathon. This also goes for hitting the Bike underprepared as well. You will be in a world of pain both on the bike and on the run.

So cyclists coming from a good cycling back ground already have a good head start in their preparation for ironman. Bike to Ironman is probably the easiest journey of the 5 possible starting points (advice for ironman beginners)

So its going to be easy?

Errr no. Easier certainly doesn’t mean Easy.

Mastering the Swim can be a challenging prospect for anyone and while you may posses the fitness. The technique side could take along time to master. The run also can be challenging. While your muscles and cardio fitness are raring to go the supporting muscles, tendons and joints will need time to toughen up to the rigors of marathon running.

But its all do-able.

If you are already doing long rides, rides in the 60-100+ miles range, you will already know about fuelling and hydration. Exercising that long requires you to eat an drink to maintain the activity. While on sportive’s and organised rides you may be used to carrying a water bottle and then stopping at set location or feed stations to refuel. This is one thing you may want to change. Most athletes do all their eating and drinking while on the move. The event will provide volunteers (Who always have my eternal gratitude) manning the feed stations as you roll by. But apart from that there is very little difference between an ironman bike leg and a 112 mile ride. Only you will have to do it by yourself.

Bike Solo


Yep Ironman is a solo event. While the hours are whiled away in road cycling chatting to your mates, or perfect strangers who are suddenly your friends. The Ironman bike leg is a very lonely event. Strict rules and penalties are in place to ensure riders ride apart and out of each others draft zone. Its a race of truth. Your time is your time not helped by riding in others drafts for part of the course.

Any TT (Time Trial) riders will be well aware of this. And will probable relish the bike leg of an Ironman. On occasion top TT riders try their hand at ironman and the performances they deliver are staggering.

But enough of what you are good at, lets talk about the bits you aren’t.



It’s pretty normal for people coming from a cycling background to find the swim quite a challenge. One of the main reasons is all that pedalling has given you strong muscular legs…that are heavy…and sink. This leads to sinky legs syndrome (I may have made that up). With your powerful legs sinking in the water it presents more of your bodies frontal area to the water.swim wrongswim right

As water has a high viscosity the drag caused by this extra frontal area is significant and can and often is the reason for slower swimming. This can however be resolved with proper technique. and its important to not get too discouraged by any initial slow progress. With time and practice you will be able to master the swim. Further advances in Wetsuit design also helps in this matter. Suits are available with more buoyancy in the legs to lift the legs up and enable a quicker swim.

where to start

Assuming you have some experience of swimming, If not you will need to talk to your local pool about adult swim classes, just head for your local pool. All you need for your first swim is a pair of trunks or a swim costume and optionally some goggles. All you are doing is getting used to being in the water. It probably won’t go too well. But that’s not the point. Its just grabbing the bull by horns. Following that its important to master proper stroke. A masters swim club or your local tri club should be able to help. However personally I self taught. Just focusing on one aspect every week.

Once the pool is mastered Its time for open water. This is where the fun begins! However unless to  are racing in warmer climes you will need a wetsuit.


The Stamina and Cardio you have built from your cycling will transfer over very nicely. As I have already mentioned though, there are a lot of support systems that will need a lot of time to adapt to running. Its imperative you start slow and steady. Minimal kit is needed to get going, shorts, top and trainers and off you go.

where to start

Just get out and run. Start very slow and very steady. Distance should be minimal, aim more for time. maybe 20 -30mins to begin with walking breaks. Never be afraid to walk. (especially during a race, but that’s another topic) Often its more productive to walk, and recover, rather than persevere with bad form and tired muscles.

Distance needs to be built slowly and steadily. Just a few mile maximum every week. and start with only 2 runs a week. a longer slower run and a shorter faster run. The great thing about triathlon is you can get away with less of each discipline. A runner only running twice a week would build fitness very slowly.

But as a Triathlete you will ride or swim for fitness while your body absorbs and recovers from the running.


Anyone already with a good base fitness from long distance cycling should adapt to Ironman training with little trouble, apart from the initial problems of swim technique. The bike section gives a lot of non bikers trouble as the skills are a challenge and the kit needed is extensive. This is not an area where Bikers suffer.


You might want to check out my kit section for help and advice on what kit to pick up for the swim and run sections, and also tips on Triathlon specific Bike kit.


Let me know if you are a Biker looking to get into ironman or if you have any questions about getting into ironman from a cycling background. Comment below and I will get back to you promptly. I’m always happy to talk Ironman!


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