Is there a general CTL thread?

Not a CTL chaser here although I do use it. Have heard all the caveats about it not being the same thing as fitness. Is there a thread on here discussing it in general terms?

The reason I asked is that for various reasons mine is tanking right now but a couple of weeks ago I hit a PB on a reference climb. Even then I knew I left some juice in the tank. When I set the previous PB I had my highest CTL of the past few years, twice where I am now, and was specifically rested to hit that PB. So I am curious what is the point of CTL beyond indicating your capacity for training? I mean I tend to use it just for that. To indicate what TSS I can reasonably cope with. Is that all it is really? I read all the TP stuff but it is more on the What than the Why and How side of things.

its been discussed in several threads. Realize you’ve seen TP stuff… however just in case you haven’t seen it, Joe Friel’s 3 part article has some good general principles on CTL and PMC:

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Yep read that. I used the principles laid out in there to plan my A race tapers. It was a total god send and put me on the road to TR so tip of the hat to TP. I am just left a bit clueless as to how I can break a PB more or less by accident with half the CTL and about the same TSB and road conditions, or thereabouts. I get it that the power curves may have been very different but it just seems a huge disconnect to me.

Opinions differ, mine is that CTL is a general trend line. More art than science.

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CTL can tank for one of two reasons:

  • You are doing less of the same type of training
  • You have increased your high intensity efforts and reduced your longer aerobic/tempo efforts (i.e. the workouts contributing to your CTL are different)

If your training was more of the former, there is probably something else contributing to your PB (e.g. more rested). Under the latter, you were better trained for the specificity of the PB you are referring to.

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I try not to sweat CTL too much, I do feel super awesome when it’s over 80. Going into next year I want to focus a bit more on keeping TSB in a good space, I had read a blip by Joe Friel that suggests keeping TSB between -10 to -25 (or something like that) for effective training. I feel like my training from Dec-April really had me in that area for a good amount of time and my fitness did improve. Over the summer I was riding and maintaining CTL but my TSB was kind of hovering around zero and I definitely lost something (I’ve backed my FTP to 285 where it had been up to 300-310). I like getting to a good CTL to allow me to ride long rides back to back and enjoy the weather, but as primarily a CX racer I don’t need a big CTL, so I definitely have to try to plan next year to have more block of consistently negative TSB

OK I buy that. There was a general build thing going on with the high CTL moment. While it would be a stretch to call what I have been doing the last few months structured, there was a mindfulness to it. I was looking at a Flanders loop so I kept the intensity up and episodic for most of the summer rides in simulation. Whereas in the past I may have gone long and steady instead. I guess it just highlights the limitations of trying to quantify this in any general way.

I should just clarify that the climb was a short power climb so VO2 most of the way. Which jives with the specificity of the training argument.

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Oh I hear you. That is the way I have been predominantly using it. Just focusing on TSB and letting the CTL do whatever.

CTL (along with ATL and TSB) can be a very powerful training metric, but not on its own unless your training doesn’t change. For a deeper understanding of your training cause/effect leading to results, you need to track CTL along with the time you spend in each of the zones (TiZ) you train in. For a VO2Max type PB effort, you’ll particularly want to look at time in sweet spot, threshold, and VO2 training zones.


While I haven’t seen the “blip”, I imagine that he is referring to a steady ramp period. Generally it will fluctuate a lot more. For example, in training for a hilly century when you can benefit from really hard, really long outdoor rides, you may drive your TSB to -40 or even -50 (i.e. on a steep ramp in CTL/fitness). And similarly, between 2 hard training blocks you may have a “rest week” where TSB goes to 0 to +10. And, of course, when you get to an A or B event, you may be targeting +10 to +25.

I’ve read most of Friel’s blogs and books, here is one example:

For most athletes I’ve found keeping Form in the negative 10 to negative 30 range when the training is hard and focused is a very productive and healthy range. This could be, for example, in the serious training weeks of the base and build periods. In this range the likelihood of a breakdown is kept in check.

As well as the above IMO it also depends on how and on what training you’ve built your CTL off, it makes a massive different.
A higher CTL built off training that is specific to ones specific or targeted PB (race, duration of PB etc) normally does correlate with a higher probability of achieving a PB result. This of course is dependant on being rested and the optimal TSB for a given athlete, for some it is 10 - 20 others it might be -5. Look back at past records for a clue.
Also based on personal experience it isn’t the just the TSB that matters its how long and quickly it has been at the optimal level for the athlete or time taken to get to an optimal level.

I could be wrong but I think you are confusing absolute numbers and relative numbers. My understanding is that the CTL formula is based on TSS over time and TSS depends on FTP. As your FTP goes up, the same level of work results in a lower TSS thus lower CTL over time. As your fitness (i.e. FTP) goes up, I think it is quite possible to get in a situation where your CTL absolute number is “down” from a previous peak but in actuality you are still a stronger more fit cyclist.

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I find the most value by having an easy way to look back and identify trends. I can easily tell where my training was consistent, or where I was ramping up or down. And then I can look back at how my fitness was changing relative to that chart. Generally, when I’m consistent, I see the greatest fitness gains.

Looking at my last season, I had an upward trend from Sept 2018 to June 2019, which was about a month prior to my A race. I felt like my consistency the last month leading into that race was poor, and my chart reflects that. And I’ve had a steady downward trend since, only ramping up as of a couple weeks ago, as I’m feeling the bug to start riding again.

That also tells me how long I was able to build for, before I started to burnout and loose motivation. I started up again September this year, and I have an earlier season race I’m targeting as my A race. Based on my past chart, I feel confident I can train till spring, race well, and then give myself a break.

I’ve also hit the training fairly hard the past couple weeks. My TSB as of today is at a record low of -36, after having a particularly big weekend. I have time in my schedule to ride today, but not tomorrow. I’ve planned two days rest to give myself time to recover, and I’ll get back on it after. Looking back, I’ve had a lot of productive training blocks where my TSB peaked around -25 or so. The chart is an extra data point, which I can use with RPE and my overall feeling of fatigue to help choose how/when to ride.

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You do touch on something here about the PMC. I find myself doing as you do with it but not just for training purposes. The advantages of a general digitized life…I cross reference it with other health metrics. It gives me some richer insights. For example I know that if there is a rapid fall in my CTL to below a certain threshold then my sleep quality goes out the window. So I have to gun for a managed off load now. How much of this is real or in the head? I don’t know. Correlation is not causation and I am an N of one but it seems to work for me.

This. I’ve about 15 CTL lower this year but faster overall in my races. Smarter training with less TSS filler and more specific intervals

This book is worth a read.

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