Setting W' correctly

[Alastair Bailey]

Hi folks,

After an FTP test I know my FTP is 230w and therefore input this in the 20 min power (243w) along with 3 minute power into the CP W' estimator.

However since training on these numbers it appears my TSS is very very high for sessions (more than I was tracking offline).

Could someone please help how is best to define an accurate W'?

[Ryan Switala]

TSS is not affected by W'.TSS for a ride is determined from normalized power and duration of the ride and FTP. What is the Intensity Factor (IF) you are getting for rides? If close to, or above 1, for a ride longer than 30-40 minutes it might be a clue that your FTP is actually higher than what you have it set at which could cause high TSS values.

There is a detailed thread on setting W'

[Alastair Bailey]

Cheers Ryan - I've been getting close to, if not exceeding 1 on my rides, nearly even had an NP buster for a 90min ride which is what made me start this thread. Could you share the w' thread?

I need some help getting CP and W' set spot on I think!

[Ryan Switala]

Here is one of them i think

https://groups.google.com/forum/m/#!searchin/golden-cheetah-users/w$27/golden-cheetah-users/iIZV2ZwzHRs

[Ryan Switala]

[Alastair Bailey]

Doesnt take me to a thread? Just the overview page?

[Nathan Townsend]

Did you enter this value in the athlete properties tab?  GC calculates TSS based on the value entered for CP under tools->options->athlete->power zones.  As long as this value is set correctly to your FTP estimate then your TSS values should be normal.  However, doing this will alter the work-balance model calculations.  CP will now be underestimated and this has the effect of making any interval session look harder than it really is. Therefore, W'bal will go deep into negative territory if you do a max effort interval session.

At present there is no way around this.  There needs to be a separate entry for both FTP and CP (or an auto estimate of one based on the other or something).

[Alastair Bailey]

Cheers Nathan. Makes perfect sense now. Will set as FTP as I use TSS / CTL / ATL to manage training currently.

[Nathan Townsend]

On Tuesday, 27 October 2015 19:37:08 UTC+3, Alastair Bailey wrote:

Cheers Nathan. Makes perfect sense now. Will set as FTP as I use TSS / CTL / ATL to manage training currently.

This is really only necessary though if you wish to compare your own personal TSS values to those of others who use FTP as their performance anchor point.  If your main priority is to examine your own training patterns then using CP as your fitness anchor point will introduce a uniform systematic downward bias to the TSS values.  These are arbitrary units anyway so the absolute value itself does not matter.  It is the loading pattern over time that is important, and this won't change.

A workaround though is to enter both FTP and CP into the athlete properties and give them both some date way off in the future.  Then just make FTP current when you want to examine TSS (and compare those values to others) and make CP current when you want to examine the W'bal model results.