Ask the Experts: Building Chronic Training Load
Thursday, March 29, 2012 at 8:00AM QUESTION: I’d like to know how my Chronic Training Load (CTL) as shown on my TrainingPeaks Performance Management Chart should change throughout the season. Should CTL be at its highest at the end of the base period (when volume should be highest), or should we look to increase CTL all the way through the build period? And is there a recommendation for percentages of increase/decrease as you move from training block to training block?
ANSWER: Great question. CTL or fitness should steadily build throughout the season leading into that next “A” event. Remember that CTL is measured in terms of TSS points and represents the overall quantity (i.e. combination of frequency, duration and intensity) of training that you have been performing over a substantial period of time (several months or more). CTL should not begin to plateau until you begin to taper, at which point your CTL will slowly drop and your level of current training fatigue, or ATL (Acute Training Load) will more rapidly drop. If things go as planned, this will bring you into great shape on race day. If your taper goes poorly by not having the proper mix of volume and intensity, much of the work of building up to the “A” event could be wasted.
Fitness occurs over long periods of time, whereas fatigue occurs in short periods of time. To raise CTL you need your Training Stress to exceed CTL more often than not. The rate at which your CTL should climb is very variable athlete to athlete, but generally 5-8 TSS/day per week is a good ballpark to start with. See the diagram below for illustration.
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The higher your cumulative (absolute) CTL, the less you will be able to load. Keep in mind too that after several weeks of building CTL your fatigue level will be high and you will need a recovery to prevent overreaching. At this point, the ATL will drop for a week or so, but CTL may continue to climb or at least remain flat.
Remember, the name of the game is consistency and this is the key to success. Tomorrow’s workout builds on today’s. Don’t try to build to much too soon or you may be setting yourself up for poor training quality due to accumulated fatigue, while also increasing the likelihood of breakdown (ie. overuse injury, illness or the early stages of overtraining).
Never compromise recovery to gain fitness. It doesn’t work.
Want to learn more about Chronic Training Load, Acute Training Load, and Training Stress? The related article "What is the Performance Management Chart?" explains how these metrics can inform you about your training and fitness so that you are at peak performance on race day. You can get access to these trademarked metrics and the Performance Management Chart by using TrainingPeaks online training log for athletes.
Jeff Vicario is an Elite TrainingBible and USA Triathlon Youth and Junior Certified Coach. He coaches athletes of all levels to extraordinary results ranging from first time racers to Ironman personal bests in addition to increasing youth involvement in triathlon, promoting healthy lifestyles and encouraging participation and achievement as the head coach of Southern California’s Youth and Junior Team I Tri (www.teamitri.com). For more information about Jeff’s coaching, to ask a question you’d like to see here on the TrainingPeaks blog, or to simply contact him for further information, you can email him at jvicario(at-sign)trainingbible(dot)com.
Reader Comments (8)
Is Chronic Training Load a 2 to 3 month rolling average of your daily TSS points, while Acute Training Load is a 5 to 10 day rolling average?
Bill –
CTL is calculated as an exponentially-weighted moving average of daily TSS values with the default value set to 42 days. CTL is a relative indicator of changes in performance ability due to changes in fitness, not an absolute predictor
ATL also calculated as an exponentially-weighted moving average of daily TSS with its default value set to 7 days. ATL is a relative indicator of changes in performance ability due to fatigue, not an absolute predictor.
I hope that answers your great question. Thanks for asking.
Jeff
I have asked this before without much success. Do you either know the underlying formulas for ATL & CTL, or have you seen a spreadsheet with the formulas in them? It would be nice to be able to forecast where CTL and ATL will be given a workout plan.
I have been told some people have built them and I have searched unsuccessfully to find them.
I've got a follow on question - what is the best approach if CTL hits a plateau?
For me that's because I've got an upper limit of available hours per week and this is pretty much fixed all year round - so I can hit 10hrs (+/- 1hour) in the winter or summer. Therefore the only thing varying CTL is how many interval sessions vs. steady miles.
It seems counter-intuitive to do less just so I can then see CTL rise again to A race - but a plateau doesn't seem right either.
From my understanding, one need to guess how fast one recovers and then the program will calculate if you are training too much, too little or optimally. But How fast you will recover is not only individual, but will also depend on other factors (such as stress at work, how well you sleep, if you get sick, etc).
Now wouldn't it be much better to once in a while do a night (or even a 24 hour) recording of R-R data and analyze it for HRV, and actually see how well the person has recovered?
then the coach function could also be based dynamically on actual training load instead of one guessing how many hours to workout during a year, getting a static ATP and then the coach function assigning exercises based on the ATP and neither what training load you have actually achieved or how well recovered you are (both which might be far from what you thought when you made the ATP).
My 2c,
/B.
On Saturday I participated in a race on my bike and selected "race" in the Calendar Quick View. In the PMC I get 0 TSS points for this 4,5 hour effort. If I select "bike" in the Calendar Quick View I get 299 TSS points. Why?
Hugo: Sport type Race will not generate TSS and should be more for planning purposes. When you upload the workout file, you should either change the sport type from Race to whatever sport the race was (Bike, Run, etc) OR just upload the file as a separate workout choosing the appropriate sport type.
We have heard this question before, and there are development plans in place to remove the confusion. Hope this helps.
@Mike – everyone has a limit to the number of hrs avail to train. Keep in mind that the best determiner of success for experienced athletes is race specific intensity—not volume.
@Dorkingdan – You are correct in that there is an art concept to the PMC and it is not all science. The PMC is based on Banister’s impulse-response model. To obtain good results using the PMC it is important that the TSS values be based upon valid, up-to-date estimates of an athlete’s functional threshold power. This is especially true since the TSS calculated for a particular workout varies as a function of the square of intensity factor. Decreasing the value assumed for FTP increases the TSS for a particular workout. This in turn will have corresponding effect on CTL, ATL, and TSB.