Good questions from qcwtom above, but in IME athletes are very likely to plateau and experience training stagnation if their CTL flat lines for very long. Yes there will always be some variation between harder days and rest days but if your CTL remains in a narrow and relatively constant range for more than a few weeks and you haven't dramatically changed the makeup of your training such as switched to hard short efforts or are engaged in frequent racing (both can make it difficult to stay on a CTL build cycle) and the basic makeup of your training has stayed the same your process will likely stagnate.
I did fitness tests in March, May, June, July, and October. I adjusted my FTP after the May and June tests. The July and October tests showed no improvements, so I did not adjust my FTP.
In March I started with L2 stuff. In April I switched to a plan modeled after the 1st case study in Training and Racing with a Power Meter. This consisted of a mixture of intensities and volumes. For example, a week might go like this: M rest T 6x2(3) W 2x15(10) Th L3 + NP bursts F rest Sa Race Su 3 hours L2. However, all of my weekdays were split into 2 workouts, so if a day called for 6x2(3) I did 3x2(3) in the morning and 3x2(3) in the evening. I also did a 1 hour gym workout once a week, but it was not focused on helping my cycling. I worked for 3 weeks and then rested for 1 week. The testing was done at the end of rest weeks. My ATL and TSB had a very regular 3 weeks up 1 week down pattern.
You have more or less answered my first question. What about my second question? What does one do if raising CTL higher is not an option?
A couple of things. CTL as a way to track overall workload is very useful and it is a decent proxy for overall fitness or more accurately for the depth of your training base but don't take it too literally as an absolute measure of fitness. There are plenty of way to rack up big CTL that doesn't maximize cycling or especially race specific fitness but as CTL does represent your long term average daily training workload it would be hard to maximize fitness with a very low CTL. IOW, if you don't train you won't be likely to maximize fitness and your low CTL will reflect that lack of training but for someone with a lot of time on their hands it's not that difficult to rack up substantial daily TSS and over time substantial CTL based on a lot of low intensity riding that may or may not translate to the demands of your target events.
If I understand this correctly, adjusting my training zones up based on FTP increases is in-effect an increase in "resistance" and is thus an increase in "volume". Therefore, I am by definition practicing progressive overload even though CTL may or may not be increasing. Resistance is absolute whereas CTL is relative to current fitness. The problem however is that I have not seen an increase in FTP during a period of constant CTL, therefore I have not increased my resistance.
Now that we're away from the mathematical and into the real... yeah, pretty much. You are increasing the intensity of the workout, which is causing an overload. If you increase too much, you might run into problems, but that tends to be self correcting. If you're trying to do 2x20's at 400 watts, you can only "try" for so long before your body slows you down to what it can actually handle
In my personal case, I could possibly increase my CTL, but I would eventually hit a cap. I don't know where that cap is exactly, but for others it seems to be in the 100-150 TSS/day range which is where I have been playing. But anyway, my original question was a more general question about the relationship of CTL and the principal of progressive overload.
Regardless of Wikipedia's definitions, CTL plateau's are generally not a good thing. But a 20+ point swing in CTL isn't exactly a plateau so it seems like you have some ups and downs going on in there.
I think you might be missing my key point. In the definitions from the wikipedia page, intensity and resistance are different. Resistance is an absolute metric that is the same for everyone, e.g. 10 minutes at 200 watts is the same resistance for everyone. Intensity on the other hand is relative to fitness, e.g. 10 minutes at 200 watts is different for a beginner than for an elite athlete. So if I increase the power target of my workout by 10% at the same time I increase my FTP by 10%, then my intensity stays the same but my resistance increases.
Interesting, 'cos for me that would be a bad PMC resulting in results below what I could be. Too much rest for me, I cannot afford negative TSB's that large, I get no positive benefit from it (other than small ones at very, very short durations from the rest but that's irrelevant for any event). Rather than simply CTL, total area below the curve for the previous few months is much more correlated with performance, and even more so with duations longer than an hour.
I think you're trying to get more out of CTL than it really is. It's just a Chronic Training Load. It tells you how much stress your body is under by comparing the intensity of your rides to your FTP.
Fair enough and I see where you're coming from. The assumption I'm making based on the rest of this thread is that he'd reached his realistic CTL limits in terms of available training and recovery time when he hit those CTL peaks which were all roughly at the same level. From that perspective I'd rather see some backing off to allow headroom for more work than just plugging away at the same overall workload level for extended periods.
