FTP test vs Racing FTP

General Discussion
1

Hi Zwifters,

I used to do a ramp FTP test and get overestimated. I started trusting more on the The Grade test as it seems that is more accurate.

After doing 2 tests recently, my FTP was 233W, which i got a miserable “improvement” of +1 :stuck_out_tongue: . Today, racing, i just got the pop up message that my FTP increased to 244W. i think its still in the error range but i have the feeling that i could have pushed a bit more. the issue with The Grade, IMHO, ist that i try i already to push (ca. 5%) of my current FTP and burn the matches easily. Im wondering if just because i had a great 8 min power, for example, Zwift will calculate my new FTP based on this or there are other points considered. in Intervals.icu my ftp increase was credited to a 3min effort. This is what confuses me. One could do simply a great 3 or 8 min effort and would that be reliable value to calculate FTP? i dont want to start a whole discussion on FTP but i still think its important parameter to set our training zones. cheers

2

I’m not sure which methodology Zwift is using to tell us on FTP increases these days and whether it’s different depending on what session we had.

I think the sub 20min efforts FTP estimates that used to be exclusive to The Grade are now applied everywhere.

But I presume “official” ramp test and FTP workouts still use 75% of best one minute and 95% of best 20 minutes respectively.

3

This doesn’t sound right. I have personally not seen intervals use a 3min effort for FTP. Are you sure that just 3mins affected your intervals.icu FTP? It might have been a longer effort that was in that same session maybe?

I forget the time range Zwift uses to calculate FTP, it used to just be 20mins, but now they do more of a CP curve, though I forget what the smallest length of time for the effort is - someone else will remember, but it’s definitely over 3mins :slight_smile:

4

In setting on Intervals, you can set minimum duration effort for FTP estimate, by default it’s 300secs (5mins) iirc.

I used to often use 420-600secs, because most of my local 263+ feet hills would take 6mins+ to climb, plus I think I used to have a relatively strong anaerobic capacity (Zwift standard ramp test would always give me a higher FTP estimate than I could get close to for ~20mins).

5

Steve, at least it says “from 3min 40s at 330 W”

6

Supposedly the FTP increases you see when you’re not doing an FTP test use the same model as The Grade KOM now.

7

No.

Not the 8 minutes and definitely not the 3 minutes!!!

8

I would gess then thiss was a “race effect”. Not sure if such thing exists but perhaps im forced to push more during a race then climbing The Grade….its an hypothesis :stuck_out_tongue:

2 Likes
9

I’m wondering if you changed the default setting in intervals.icu? Mine is similar to what Steve said, it is showing 300seconds (5mins) as the minimum time to calculate an FTP.

Personally I think 5 mins seems a bit low to calculate FTP, but usually whatever intervals shows for me seems reasonable I guess.

10

Not that I can remember…