Friday, January 31, 2014

How High of CTL for Ironman Bike?

If you're using TrainingPeaks software to train for your Ironman event, you likely are using their Performance Management Chart, (PMC). Chronic Training Load, or CTL, is one of the key metrics in the chart. It's the long term Training Stress Score, (TSS), average. How long is long term? The default setting is 6 weeks, as a 42 day rolling average.

So when you upload your data from your ride, the software reads the samples from the data and compares those with your FTP to calculate how stressful the ride was, and then takes that score and averages it with the previous 41 days. I actually use the software to keep a separate PMC just for cycling.

The question many have when they train for an Ironman event is, "How high should my bike CTL get?" The answer to this question is, (like almost all training questions), related to your goals for the event. For example, if your goal is to simply finish the race, then a lower CTL is fine, but if you're trying to qualify for Kona, or win your age group, then you likely need a much higher CTL. If you're a pro, trying to earn a paycheck, or win the race, you should probably be even higher than what the top age grouper is achieving. If you're trying to win Kona as a pro, then you likely need an even higher CTL.

If you're looking for a bike-only CTL value to achieve in your training, the number is likely going to be related to your FTP value. Why? Because usually, the higher the FTP of the athlete, the higher the performance goal. Here's a chart for you to use based on your goals, and what I have found to be the tendency among the different types of athletes.

With sharing this chart, there are 4 important things to keep in mind...

1. This is just a guideline for PEAK CTL VALUES, mostly for seasonal planning purposes. Because of that, there will be people who don't fall into these guidelines, but I do find a majority of athletes do. I don't find there is much need to list a mid-pack athlete, since they vary the most in terms of background and training styles.

2. Your swim, bike and run skill will also play a role in whether or not you would achieve these goals. Again, this is a guideline for your bike training, knowing how much is enough, or a range of what might be enough.

3. The course an athlete races for their goal event is a big determinant of the value one should achieve as well. For the Kona Qualifier Pro and Pro Podium at Kona, that is course specific to Kona. The Age Group Kona Qualifer is general for all courses, since age groupers qualify at many different individual races. There is a big difference between qualifying at Ironman Lanzarote and Ironman Florida.

4. Your FTP will likely, (and should), improve throughout the season. For some it will improve more than others. This means your initial CTL value goal will likely change a little, so give yourself a range, or be prepared to adjust it as the season goes.

How can you use this information? Look at the end of your season, what your FTP was, the peak CTL value you achieved, and what your goal was for the event, and see how well you lined up with this chart. (Please share in the comments your results as well). You can then use this information to better assess your training, set new or different bike CTL goals for your upcoming events, and use those goals to help motivate you in your training.

Lastly, CTL doesn't win races, performance does. No awards or Kona slots for who had the highest CTL. Don't get hung up on CTL. Make sure you are seeing the performance gains you want in your training first and foremost. It's all about balancing training stress, this is just a guide to use and better understand your training, so you can improve it.

Good luck!

Coach Vance


jestromb said...

Any thoughts on ctl goals for oly racing?

zia cyclist said...

To make sure I understand, if my FTP is 210 then my goal ranch CTL would be 63-84 TSS/day or 30% to 40% of FTP. This is just for the bike. Do you also track run CTL using Functional Threshold Pace? Your goal bike CTL fits in with my experience (although I'm not a Kona qualifier). I recently wrote a blog on my experience using PMC:

Jim Vance said...

Jestromb... So many factors for Oly, which includes non-drafting or drafting, skills of swim/run, and the course. Hard to narrow down.

Zia Cyclist... Yes, that is right, but again, it varies. You might find that many Kona qualifiers are around the upper part of that range, or past it. Yes, I also use threshold pace for the same, will share that in a different post coming up.

Dan Cole said...

How does this vary (if at all) for bigger athletes who have a higher FTP but aren't necessarily any "fitter" than smaller athletes?

I'm tall but lean (195cm, 79kg) AG'r with FTP of 310. So achieving >110 bike CTL would need 2.5hr+ rides or sustained FTP interval rides everyday to get that bike CTL.

Jim Vance said...


Great question. This was the biggest feedback question I got from readers. I will do my next blog post tomorrow on this exact question.

ironmurph said...

Sorry Vance but I disagree with your relationship of CTL with FTP. CTL is already factors in your FTP

By definition TSS = (sec x NP x IF)/(FTP x 3600) x 100

By definition CTL is the summation of your TSS over a 2-6 week time period with greater weighting on your more recent workouts.

Therefore its does not seem logical to base CTL on your FTP.
My FTP is 330watts and with a CTL of around 65, but your calculation I would only be at 18% of my CTL however I train consistently at 20-25hrs a week with plenty of high quality sessions and was first agegrouper across the line at ironman cairns in 8.56 so cant be that far off optimum.

Happy for your thoughts though?

Jim Vance said...


I will fully admit it isn't a proven metric that is applicable to all athletes, especially when one has a high FTP. However, the higher the FTP, the less they need to match this ratio, because their bike is strong. So it isn't that this idea is wrong, (it's just supposed to be a guideline for planning), it just needs to be adjusted for those with higher FTP.

Also, athlete individuality should always be considered.

Congrats on your race BTW!

Coach Vance