FTP increase -> lower weekly TSS -> lower daily average TSS

Has anyone noticed a trend of their weekly TSS (and daily TSS) dipping after a significant TSS increase?

I’ve noticed that in the weeks following a TSS increase, it’s challenging to reach the same TSS as previously (likely because that TSS was artificially high since your FTP was already higher but not recorded - and now doing threshold etc at a new, higher FTP is a lot harder until your body adapts). So consequently, the average weekly TSS dips (often when FTP testing hasn’t been consistent either). Rendering the TSS data inaccurate (GIGO) And not useful as a benchmark.

So, how do you utilize your TSS as a benchmark (when not testing FTP as regularly as you should)? Should you just start subtracting x percentage the further away from the last FTP test you did?

Asking for a friend. Ok, I’m that friend. Asking for me. I haven’t been FTP testing as consistently as I should. That said, should you just assume that your TSS average will equal out and provide a reasonable benchmark over a couple of months? (And start FTP testing consistently).

Thank you for your input!

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This weeks Podcast answered the point.
Summary TSS is not all created equal.
By that chad says it all. It is just one metric to measure the stress of training. Others matter.
So You will notice that TSS does go down when moving from high base to Build as its different Stress. Threshold VO2 max hence you could get the same TSS score but it is a much harder workout.

You can go off RPE and feel, but testing gives you another metric to work off. There are other metrics… Training with Power meter book Hunter Allen and Andrew Coggan is the bible… lots of research too.

The main thing to realise is Goal setting… What am i trying to achieve? What plan best suits me? Training is hard its meant to stress you to illicit a metabolic response.

The ramp test is hard… but will give you the right training metric to work off… do not be a slave to FTP either it just refects the current way you and your body are.

The other thing is just have Fun… you get to ride a bike…


That’s an interesting question. I think a more interesting question is why hasn’t your friend been testing FTP consistently? I think that you need to ask your friend this question and drill down. Don’t accept the first answer he/she gives, as it is probably bs.

In my experience in work and in training, you should never estimate something that can be easily measured.


Testing consistently is part of the plan. Arbitrarily adding or subtracting a certain % here and there is just making the water more murky. Why spend all this time, effort and money to guess when you can know? In another thread I swear people just want to avoid testing all together for usually two reasons: it hurts and they are afraid to fail. Both are hard to take but, both are necessary. Learning usually results from pain and failure.

As for TSS specifically, pushing it up over time while in base doing mostly the same relative low intensity riding, is when comparing weekly TSS seems more valid. Switching from base to a move VO2max centric build and specialty plan then comparing weekly TSS becomes less important. Time in zones and hitting the numbers is what matters more imo.

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The whole paradigm of training with power based on FTP is kinda based on having a semi-accurate estimate of FTP. All of your training zones for structured workouts are based off your FTP. Other metrics such as IF, TSS, CTL, ALT, TSB are all derived from your FTP. If your FTP estimate isn’t semi-accurate, then GIGO. You have power data from your rides and that is about it. I don’t think there is much of use you can draw from the metrics.

That said, regular testing is a good way to establish about where you FTP is. You can also use your own feedback from workouts to adjust FTP, if you are experienced and ‘know’ what threshold feels like. You can also use models to estimate your FTP. Personally I find it difficult to perform well with structured FTP tests, so for years I used a Monod Power Duration Curve calculator to estimate my FTP off of a 20min max effort and a 3-5min max effort performed during the same week. GoldenCheetah also has a calculator. I personally find the Intervals.icu eFTP to be a bit on the high side, but that is another method.

I think the reality is that if you are off by 1-2% or 3-5 watts or maybe a little more, you might not notice. Most power meters have stated accuracy of 1%, so some of that 3-5 is in the noise. But if your FTP is 300 and you are doing 100% FTP intervals at 303 or 305 or 297, do you think you would notice?

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Simple solution: don’t use TSS.

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Maybe use Kilojoules? At least it would be a valid relative measure of actual work performed as not impacted by FTP measurement, or lack thereof… Obviously has limitations, but can provide you a consistent metric…

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This TrainerRoad blog post answered quite a bit, particularly the decrease or flattening in TSS after an increase in FTP: Training Stress Score: What is TSS & How to Use It - TrainerRoad Blog