Riding a Flat Ironman BIke Course

Time to shake things up.

We are not Robots

Riding a flat Ironman bike course should be easy. Well, it looks it on paper; let’s ignore the fact that you’ll be rolling over 180km of asphalt powered by nothing but you!

At least the plan should be easy. There are no pesky hills to get in the way. Your pacing can be dialled in at a macro level. Just find your desired effort level, dial in your desired number of watts and let it rip. PR, here we come.

Not so fast.

I have written previously about why a hilly bike course (like Ironman Canada), should not be feared. You can check that out HERE. But that fact is that a flat course brings its own set of issues.

We are not robots. And applying a robotic plan to a human frame can have consequences. Just ask all those walking the run at Ironman Texas and Arizona, lamenting the fact they “Had a great bike but just couldn’t run today!”.

Flat bike courses can beat you up.

To have a good bike when riding a flat ironman bike course, you need to set yourself up physically for the run. And that not only requires pacing but also variety.

What is Power?

Before we look at what we need to do on a flat bike course, we need to understand how our legs propel a bicycle. To keep it simple:

  • We apply torque to the pedals by pushing on them.
  • We apply this torque a number of times per minute – cadence.
  • Those two things go some way to define how quickly we move forward. 

Many of us have a power meter. A great device that measures how hard we are pushing the pedals and how many times we turn the pedals round. It then spits out a number measured in watts.

torque (pedal force) x angular velocity (cadence) = watts

This is a hugely overlooked equation when it comes to spreading your effort levels over a triathlon bike ride. Because those two things can be driven by  two differing ‘engines’. You have two ways of adjusting how you physically achieve your watts.

So, what can you do to improve your ride?


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Change Things Up

Hammering away at the same cadence and same wattage for the full bike ride is a bad idea. You will be doing the same thing over and over again, breaking yourself down and depleting your ability to perform.

Ironically, hills actually help stop this happening. Hills force you to increase and reduce cadence.  They also give you a break as you head down the other side. Breaking up your ride allows you to recover physiologically (and mentally too).

Hills add variety. This key component is often missing form a flat ironman bike course. 

We have established that both Torque and Cadence create your power.  This means that you can increase one and decrease the other, whilst maintaining the same power.

Those of you that train low cadence and high cadence may notice that your HR and respiratory rate shifts up and down as you decrease and increase cadence (the science of which is best left for another post).

This leaves you with a couple of tools to play with. You can reduce the ‘push’ on the pedals for a while and still maintain your power, just increase your cadence. Shifting the load from your legs to your cardio / respiratory systems. 

On the flipside, you can drop your cadence for a while, increasing your torque on the pedals and keeping the same power but reducing the load on the cardio and respiratory system.

With most Ironman athletes being more efficient at the lower cadence range, you will likely get your rest by spinning  the legs a little faster (cadence) and reducing the torque (how hard you push the pedals).


Variety on an Ironman Bike Course

The key takeaway from this article should be that you need variety to keep things fresh; adjusting where the load is applied to allow different parts of your system to enjoy some respite.

Increasing cadence and reducing torque on the pedals does not kill your bike time and can make or break both your bike and the run.

Ensure you are getting coaching that cover a range of cadences, from very low to very high, can help improve the bandwidth at which you  are very comfortable riding. Using this bandwidth in training can have a great effect on your performance.

Combine this with the regular shifts in bike position and even power output. Allow your body to ebb and flow with energy changes. We are not robots, and learning to adapt to your physical needs on the fly is an essential skill for establishing a great Ironman bike performance. Your run will thank you for it too.

Hope that helps and have a great race!



For more tips like this, check out our 140.6 and 70.3 Training Group on Facebook.  

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