How To Pace An IRONMAN Bike

Your IRONMAN bike pacing strategy will make or break your race. Here’s how to get it right…

IRONMAN is an endurance trial, not a race. The most successful IRONMAN athletes know exactly how to pace themselves and have the mental strength to execute their pacing strategy on race day.​The bike section is where pace judgement is most vital. There are three big mistakes that people make here.

  1. Attempting to ride at a constant power output that is slightly too high.
  2. Riding in bursts, ranging from easy to hard – without realising.
  3. Riding too hard on the hills, due to inappropriate gearing.

All three of these mistakes cause fatigue with no overall benefit. They make you tired, they make your stomach feel crap and they make you want to quit. Get it wrong and you’ll struggle to ride 112 miles and run 26.2 miles.

Why I’m Passionate About IRONMAN Pace Strategy

In 2015 I did IRONMAN Barcelona, having recently become a new Dad. With a full-time job, I could only average 7-hours per week in training.  I did a total of just two long rides and one long run in training  – and all my other workouts were 60-minutes or less. I was therefore very nervous about the IRONMAN and knew I’d have to get my pacing right to stand any chance of surviving.

On race day I followed the pacing strategy below and I actually set a new personal best of 8 hours 55 minutes. I was pretty shocked. I don’t even consider myself a natural endurance athlete – before I discovered this pacing strategy I’d always bombed at long-distance events.

It was like a revelation to me and I believe anyone can benefit from this approach. Lesson one is to not base your pace strategy on the bike split you’d ‘ideally like to do’. Instead, follow the advice below and your speed will take care of itself.

What You Need

You need a power meter to get your pacing right. If you don’t have one already, I recommend you buy one now. You might not want to fork out money on more equipment but trust me – it’s one of the best purchases you will ever make. A power meter will massively increase your chances of success at Ironman. I used a Stages Shimano Ultegra, costing around £500.Note: For Heart Rate and Feel guidelines, I created a more recent blog.

But don’t stop reading this one yet.

Test Your Power Output

Once you have a power meter, you’ll need to get an accurate idea of your own power output. To do this, you should conduct a 20-minute time trial, known as a “CP20” test.

It’s REALLY SIMPLE to do. You simply ride as hard as you can for 20-minutes and record your average power output. See our video on this page for more guidance.

Once you know your CP20 power output you can work out your Functional Threshold Power (known as your FTP). It is a common measure of cycling ability and it’s SUPER EASY to estimate…Simply multiply your CP20 power output by 95% to get your FTP.

Example:

If your CP20 power = 200 watts

You would multiply it by 95% to get your FTP.

Therefore, your FTP would be 190 watts.

Once you’ve done that, you can use the IRONMAN pacing guidelines below:

Pacing Strategy

Use a power meter (if you have one) to pace yourself on the bike, with heart rate and RPE (feel) as backup measures. If you don’t have a power meter, just use heart rate and RPE instead.

Check our Triathlon Race Pace Calculator to help guide your pacing strategy.

Riding at the right intensity takes discipline and courage, especially when other people are overtaking you. But it works. At around the 80-mile point, you’ll notice people starting to drop off, while you continue to ride strong. You’ll also find it easier to digest your race nutrition, helping you maintain your energy levels going into the run. You will run faster as a result of pacing yourself properly on the bike, and you’ll feel fresher and more energised.

-- CONTENT CONTINUES BELOW --
Kickstart Your Training Today!
Choose from over 900 plans from 4-48 weeks long in beginner, intermediate, advanced, masters and off-season versions!

Conclusion

Riding at the right intensity takes discipline and courage, especially when other people are overtaking you. But it really works. At around the 80-mile point, you’ll notice people starting to drop off, while you continue to ride strong.​

You’ll also find that you can digest your energy drinks and energy snacks far easier, which helps you maintain your energy levels going into the run. Therefore, you’ll actually RUN FASTER as a result of pacing yourself properly on the bike, and you’ll feel fresher and more energised.

Intelligent pacing leads to faster, more consistent IRONMAN results – and yet hardly anyone gets it right. I just hope this triathlon coaching blog helps you make the right pacing choices at your next IRONMAN. Good luck!

Share
Share
Share
Share
Print
Phil Mosley (Coach & Founder)
Phil Mosley (Coach & Founder)

Phil is a recognised endurance expert who founded MyProCoach in 2010 to offer smart training plans that still leave quality time for your family, friends & career - complete with highly-rated coach support (he has sold over 40,000 so far). Learn more here!

As featured on...

IRONMANU_Logo_full
download (1)
trainingpeaks_logo_vertical_2-color
Cycling_Weekly_logo.svg
GTN
220 triathlon

Popular Articles from the Training Tips Blog

ONGOING FREE ADVICE FROM RECOGNISED EXPERT PHIL MOSLEY

Sign up for Phil's email newsletter!

Get expert training advice, the latest news and occasional discounts. You can unsubscribe at any time.

Kickstart Your Training Today!
Choose from over 900 plans from 4-48 weeks long in beginner, intermediate, advanced, masters and off-season versions!
Planning Your Off-Season

You can start our Off-Season (Fitness Maintenance) plans anytime you like.

They’re designed to help you maintain a good level of fitness when you’re not specifically targeting an event, such as, during the off-season, or anytime you’re taking a break from racing.

Planning For Your Event

For the best outcome, input the date for your “A” target race and the tool will default to a plan that will fill that gap nicely. If you want, you can then adjust the plan length to start it on a different day.

Note that you can still work in other, smaller races during your plan too!

The longer plans start easier and progress more gradually. This has a bearing on the difficulty level you choose. For example, a 12-week plan starts off at a higher level than a 36-week plan because with 12 weeks left there’s not as much opportunity to build up slowly.
Short Medium Long
Duration
4-12 weeks
14-24 weeks
27+ weeks
Required fitness level
Higher
Moderate
Lower
Training phases
2~4
5~7
8+
Fitness tests
1~2
3~4
5+
Our Standard and Masters plans are designed to get you ready for your target event, while our Off-Season plans allow you to recover from a tough season but still maintain your well-earned fitness.
STANDARD MASTERS OFF-SEASON
Approx. age
Under 40
Over 40
Any
Recovery weeks
Every 4 weeks
Every 3 weeks
N/A
Strength sessions
1-2 per week
2 per week
1-2 per week
Likely goal
Train for event
Train for event
Maintain fitness
This table provides a brief overview of which level might be right for you, to help you get the most out of your plan. You should also note your current fitness levels and how many times you have done this event before.
BEGINNER INTERMEDIATE ADVANCED
Experience
Little to none
1-3 years
3+ years
Time to train
Limited
Moderate
Ample
Likely goal
To finish
At least top half
Competitive
All our plans are available either for sale directly on the TrainingPeaks Store (where you can also see screenshots of sample weeks), or you can subscribe as an Unlimited Athlete to be able to swap freely between all of them, among other benefits outlined below.
BUY SUBSCRIBE
Price
$24 to $159 per plan
From $24 per mth
Flexible, structured training
TrainingPeaks training app
Coaching videos, articles & FAQs
Email coach support

During plan only

Anytime
Swap freely between all 900+ plans
Help setting up your training zones
Coach fortnightly engagement check
Discounted TrainingPeaks Premium (optional)
30-day moneyback guarantee
We're Sorry To See You Go!

Please confirm your cancellation below and one of our team will process it as soon as possible (stopping all future payments). Your subscription will still continue until the end of your current billing cycle (your “next payment date”) and there is nothing else you need to do.

Don’t worry, you will always be able to access your completed workouts and your TrainingPeaks login credentials will stay the same. Also, if any payments happen to come out before we cancel your subscription, we’ll simply refund them.