Under target TSS for Sunday Z2 ride

Hi All me again lol

Started 18 weeks SS last week with FTP test, set up everything and completed first week no probs, great support with my few questions :+1:

Sunday I had a 1.5hr Z2 ride with target TSS of 75, I rode the session and kept my power in the upper half of my Z2 but only managed a TSS of 63 - I still turned it green but should I have kept riding to his the TSS of 75? What exactly does this mean, could my FTP be different (higher) than what I tested at? That being said I have been riding nothing but Z2 pretty much 5 days/wk since end of Nov/Dec on avg about 2 - 2.5hrs/ride before starting my plan.

As I’m used to riding 2hrs/day, starting tomorrow I’m going to add an additional 30mins Z2 on to the end of my workouts, my thought is this should help with with overall TSS by end of week. Thoughts?


First thing to check is that your tested FTP is what you have manually entered into training peaks. Settings->Zones->Power

If you tell TPeaks an FTP that is too high for the zone calcs from the Fascat spreadsheet, it will calculate TSS too low. Similarly, tell it an FTP that is too low vs the spreadsheet and your TSS will be calculated too high.

Yup, double checked everything & all good & as it should be.

My previous workouts earlier in the week were on point, it’s just the Z2 ride on Sunday I was short.
My tested power was 226 so FTP is 215

Fascat SS Zones

Just looking to correct whatever it is before anything goes crazy and ends up really off.


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Looks good, I don’t have another guess. Looking back at that ride on my first week of ss123, the tss was right on.

Check your overall average power and normalized power for that ride. Based on your power zones they should both probably be somewhere around 150-155W. If it’s much lower then your TSS will be under target. The TSS calculation is assuming you hold ~72% of your FTP during that Z2 interval.
For these workouts I like to set up my bike computer to show average lap power or average lap normalized power. This way I can track how my power is averaging over that long 1hr20m interval.

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@Gavin - Hard to say without looking at your trainingpeaks, but it could be due to time spent descending (which average power would reflect).

But to answer your question about zone 2, yes that will help to achieve your TSS… or bump you over which may not be a bad thing if you are able to handle the volume and it does not impede your ability to FtFP your key workouts.