Intervals.icu FTP vs. AIFTP- Huge difference

Training
27

Based on the graph of your 2min effort, I wonder if you might be able to hit the 400W for 2min if you started off at a slightly lower power. Maybe something like start out around 410-415W and just try to hold on. I think one key to focus on in an effort of that length is to know what gearing and cadence you plan to hold for most of it, then try to get your breathing in sync for the “middle” section.

I used to do semi-regular 500m tests on the rowing machine, which were usually slightly under 1:30. While that’s shorter than a 2min effort, I think the duration is similar enough that the pacing ideas transfer. The key for me was that steady-ish rhythm from about 15sec through about 1:05 or 1:10. After that I was definitely just trying not to fade too much. :slight_smile:

1 Like
28

I’m sure it’s possible, I was going for a Strava KOM and it wasn’t an all-out effort.

29

Thanks for your answer. I know this about max effort, which is what I meant to say in my first sentence.

30

Confirming what @WindWarrior said – Intervals.icu requires a capacitive effort, while TR’s AI FTP Detection uses Machine Learning to analyze millions of rides to understand how FTP changes over time and in response to training. Our system looks at your personal biometrics and the unique details of your recent and past cycling data to detect your FTP without the need for maximal efforts or specific workouts.

2 Likes
31

My AIFPT is 272
My Intervals.icu eFTP is 253
My WKO5 mFTP is 242

I’ve done max 30 sec, 5 min, and 20 min efforts all within the past 90 days.

I usually do workouts with the TR AIFTP prescribed watts, but when I’m not able to hold those watts for certain workouts I justify it by telling myself I’m still within the prescribed range according to WKO5 lol

32

My AIFTP is 284, setting Intervals for 600s, which I think reflects better my characteristics, it gives me 280w, which is quite close.

33

I always felt like AIFTP gave my ego a nice FTP, but in reality it was higher than it should be. When I used the FTP it gave me, all my workouts felt way too hard.

WKO5 and Intervals.icu always felt like a much more realistic value. Xert on the other hand was always crazy high. I’ve been using the WKO5 numbers and my workouts feel much more manageable.

1 Like
34

intervals.icu isn’t always super smart, I did alpe du zwift yesterday and at 25mins shifted a little into tempo for a few before I picked it back up and the detection only used the higher 25min segment (even though my 47min power was 297)

image
image874×609 73.9 KB

1 Like
35

GoldenCheetah’s interval detection is soooo much better. For all the hoopla about Intervals, it falls over on the job defined by its very name!

36

Yeah it started with interval detection but since then I have been busy with all kinds of other stuff and haven’t had a chance to go back and make that better. Endless todo list. Must put less bugs in the software :slight_smile:

People on this thread have eFTP about right. It needs a max effort long enough so your anaerobic side of things doesn’t skew it high.

Intervals.icu tracks a “rolling” eFTP number that decays slowly if you reduce training load and goes up if you do a good enough max effort. That is the one that is used to generate the “FTP Up” achievements.

If you look at your power curve for a specific time period then another eFTP number is displayed on the chart. This is the best eFTP for that power curve.

19 Likes
37

Yes but there is no difference between 303 and 297 - it’s the same number when it comes to FTP :slight_smile:

3 Likes
38

WKO5 seems to need a longer effort in my experience. When I do a Kolie Moore 35-45 minute ftp test, my WKO5 mFTP is bang on every time.

39

The unpopular opinions thread is that way :point_right:

6 Likes
40

@davidtinker Thanks for your work on intervals.icu. I dropped the paid version of Strava and I’m paying you now. It’s really flexible; nice piece of work. :pray:

2 Likes
41

Thats what success does! FYI - I tried the Garmin secondary target support and it doesn’t work with HR (as per the thread on your forum). Once I have a chance (next week), I will post full details on your forum about the missing fields in your workout.fit (I completed initial analysis comparing Garmin workout vs Intervals workout, want to start clean and properly document for you). Cheers.

2 Likes
42

I’ve found certain TR workouts will trigger an eFTP detection but most don’t. Merriam gave me an eFTP of 191, at that time my AIFTP was 226.

43

This is the correct answer. Intervals.icu will give you the same eFTP if you one 3 minute interval at say 350 W or if you do ten 3 minute intervals at the same wattage, assuming the rest intervals are not super short. AI FTP Detection will take the full workout into account and understand that your FTP is likely to be higher.

46

Yes, that was my point. If you can repeat it you are not doing an all out.

But AI FTP Detection is happy to increase your FTP even if you are only doing sweet spot intervals.

47

Only have power readings from my trainer and only do TR so Intervals ICU FTP will likely always be pretty far off.

1 Like
48

I did my first long hard outdoors effort the other day since starting TR training (and intervals.icu use) in December, and intervals has gifted me an eFTP of 304W, based on 9 minutes at 344W.

My AIFTP meanwhile, taking into account the same ride (and a bunch of TR workouts, but not loads as I’ve been mostly unstructured outside riding recently) bumped up from 279W to 282W.

I prefer the eFTP number, naturally. Especially since at 75kg it sees me breaking the magical-seeming 4W/kg barrier :grin:

That said, while it’s s that time of year where I’ll now barely touch TR until October, I’d be reluctant to set my FTP on there to 304W. I think some workouts might suddenly become a bit TOO challenging!

1 Like