Eftp or ftp for indoor training?

Hi everyone,

My racing season is over and my work schedule has gotten busier so I am planning to get back on the indoor trainer during the week and ride outside on the weekends. I like using erg mode when riding indoors and right now I am focusing mostly on Sweet Spot and Zone 2 rides on the trainer.

I know I should just do an FTP test but I am hoping I can just plug in a number and get going. However, should I use my 42/90 day ftp (both the same) or should I use my current eftp which is 10 watts lower?

Thanks for any help you can provide!


I’d go for the 90day eFTP which will probably also keep decreasing if you’re only doing the type of rides you mentioned. So eventually you should do some kind of max effort to keep your eFTP up-to-date.

Thanks for the reply. What would be the minimum max effort I would need to do to keep my eFTP up to date? 1 minute? 5 minutes?

Anywhere between 3m and 20m.
Go to your settings, and look for the value:

1 Like

Got it, thanks! Mine says 300s.

1 Like

What do you recommend for the eFTP min duration setting? Mine is at the default 300s and I noticed yours is at 1200s. I am training for crit racing so most of my races are in the 45 min to 55 minute range. Does that make a difference with what I choose? The fact that I am interested in a lot of power but for a shorter duration? I ask because I get different numbers depending on what I enter. Three minutes through nine minutes is the same, but it starts to drop once I hit the 10 minute range.

It’s not so much dependent on the type of racing you do. It’s more dependent on your personal power profile. If you know that you have a higher then average anaerobic capacity, it’s better to lengthen the duration setting. That’s to avoid getting a overjudged FTP caused by your better anaerobic performance. Short durations of 4 min and less will be skewed by your high anaerobic capacity.
If, on the other hand, you’re more a TT type with less anaerobic capacity, shorter duration will yield very much the same result.
If you see a drop of with durations of 10 min and higher, it’s probably because you’ve never done all-out efforts longer then that. 10 min is too long to be highly influenced by anaerobic. Maybe you did regular VO2max blocks but never longer durations at max effort.

1 Like

ciao, se fossi in te la prima cosa che farei è quella di togliere la funzione erg. successivamente farei un test ftp qualsiasi considerato che starò in transizione prima della build e invece di farlo da 20’ lo faccio da 23’ sapendo che tutte le piattaforme per interesse commerciali danno ‘valori non corrispondenti mentre a 23’ prendo il valore assoluto in quanto la flessione diventa fisiologica;. saputo il valore senza scarto, aggiusto l ftp sul trainer; e il valore dei w’ continuamente se m interessa sapere i punti di ricarica O2. se proprio non vuoi fare un test, prendi una CP di un workout durante il quale ti sei sentito molto bene e inserisci il valore espresso ai 19’. Divertiti

1 Like

As the others have already answered your question on what setting to use, I’ll explain why mine is 1200s.

I find that most of my athletes have an FTP that is set too high, possibly indicative of the anaerobic contribution on those shorter, but harder efforts. I’ll use 300s when I’m doing VO2 work in the last half of my build phase, as I won’t test FTP before the first A race race.


Thanks for the reply. Sorry if this is a dumb question, but how would I know if I have above average anaerobic capacity?

Intervals lists me as an “all-arounder” and WKO5 says I am a “time-trialist”

You do race crits, so you should know how you compare to others when accelerating out of a turn or sprint up a short hill. If you can easily stay in the front during the last quarter of those races, you are someone with a higher anaerobic capacity.
People who perform better around threshold or high tempo, will choose other types of events to participate in or will handle those crits in a different way. Longer escapes for example.
You can check out the Power page to compare to other Intervals users to get an idea too.

1 Like

Here is how I compare to other males:

Also, I can usually accelerate away from the pack any time I want in a crit, but I can’t hold it for long. I also find short Vo2max and anaerobic workouts easier than longer threshold workouts.

If that is the case, would you recommend setting my eftp setting to ten minutes or longer since I am moving into my base phase and will be focusing on long sweet spot intervals? For example, I am starting with 4x15 at around 85% of ftp today.

You look strong all over the place in your age category :+1:
What if you compare to a younger age cat? How hard do you perceive those short bursts? Have you ever raced with a larger group of athletes that are considerably stronger then you? Were you gapped on longer steady efforts or during those accelerations?
All things that can help you evaluate what type of rider you are.

1 Like

I can usually hang with most groups but if I throw down a big effort, I run out of steam and the group can ride away from me. In my most recent race (Cat 4), I tried a late race flyer at the start of the last lap and was able to hold it until the final turn when the whole field swallowed me up and I went from first to 22nd. :slight_smile:

Would you recommend setting my eftp setting to ten minutes or longer since I am moving into my base phase and will be focusing on long sweet spot intervals? For example, I am starting with 4x15 at around 85%-88% of ftp today.

Would you recommend setting my eftp setting to ten minutes or longer since I am moving into my base phase and will be focusing on long sweet spot intervals? For example, I am starting with 4x15 at around 85%-88% of ftp today.

Why is 90 day better than 42 day? Wouldn’t more recent data be better than old? I have no idea, trying to learn.
Same for W’ value in S4Z then I guess. Better use 90 day value? I used 42 day value now since I “thought” it would be better

Without knowing your history, it would be a complete guess. What ever you set it to, it needs to be a max effort. A week spent doing some maximal effort is not a week wasted, especially if it’s at the start of a new base block.

This is why Tim Kusick (WKO5) suggests a range of max efforts, i.e. 5m, 20m, 1m and 2x max effort sprints (1s and 5s) spread over a week of testing. Neal Henderson (Wahoo) believes in doing it all in one session, i.e. the 4DP test. The test protocol for INSCYD is also some short and longer duration efforts (up to 12m). Once they have your power profile, you know where to start.


A range of max efforts over time is also the prescribed protocol in Training and Racing with a Power Meterfor (Hunter, Coggan et al). In my (often confused and deranged) mind some of the details are not as important as long as you do enough, they are max effort, and you use the same protocol every time.

Would recommend reading that book for anyone interested in training with power.


Quick update:

So my eFTP setting had been at the default 300s which gave me a 90 day FTP of 295. But since I think I lean more towards an anaerobic athlete and I want to focus on growing my TTE this offseason, I switched the setting to 1200s, which gave me an eftp of 266. Big difference. So long story short, thanks to your encouragement, I finally did my first ever 20 min FTP test (I have always used the ramp test or just used websites like intervals.icu that estimate it for me) and below is the email I just received: