Is there a way to reset eFTP?

I took a 6 week break from ~Thankgiving to the new year and my eFTP stopped dropping and is still at the pre-break level, even though none of my recent activity eFTP’s have been over it. I’d like to drop my overall eFTP down so I can see my improvement for motivation purposes.

-Rob

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Thats a good idea. I have added it to the todo list. Will try get it done this weekend.

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Its not done yet but well in progress. Implementing this and changing the fitness chart parameters by adding calendar entries:

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Wow, that’s awesome and exactly what I want and, I hope, others would want too. Seeing your FTP/eFTP increase is a nice motivator.

Thank you, David.

The set eFTP part of this is finally live. Turned out to be trickier than I expected!

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I started using it as soon as you posted and I reset my eFTP down on 1/1/20 and now I can see it starting to ramp back up already, it’s perfect David. A big thank you for what I hope others will be able to use too, especially with the new year and people taking time off for the holidays.

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The feature seems useful, especially in the winter months. I experimented with it and came across the following: the actual algorithm used for estimating FTP might be expanded to judge from submaximal efforts. As far as I remember, @david, FTP is determined by comparing a maximal effort to real power curves. If this is the case, could you possibly use HR data to judge if a submaximal effort indicates a higher FTP? For example, I’m doing sweet spot sessions right now at 280W at around 10 bpm below my FTHR, but still my eFTP is at 277 (obviously, 0,95 * 280 ist less than 277, so no need to update if you use the conventional logic)

Yes you are right max efforts are used to pick power curves and hence FTP. I did consider looking at HR data to try find sub-max efforts. There are lots of things to consider. Do I look at average HR or max at the end? What if the athlete hasn’t warmed up much so HR starts of low and takes a while to kick up? No coffee that morning? My worry is that there will be a lot of variation in HR and I might end up overestimating FTP but it would be awesome to find a way to make it work.

Here is an example. I had only been riding easy for 5 mins with stops for traffic lights when I started this effort so my HR takes a long time to respond.

Screen Shot 2020-01-20 at 17.23.09

On a related note if you repeat efforts within some short timeframe then that also indicates that they are sub-max (e.g. the 2 x 8m FTP test protocol) and any FTP derived from one of them should be higher. But what is a “short timeframe” relative to the interval length and how much should this raise the estimate? I am not aware of an accepted fatigue model to try answer the “what should you be able to do now given what you already did on the ride” question.

I could do something specifically for the 2 x 8m test.

You are right; I’ve come up with several theoretical approaches, but none of them is really rigorous and applicable to noisy real world data. Here are some thoughts nevertheless:

  • from the rider’s history, you know more or less what an athlete’s HR zones are. I can imagine some sort of empirical correlation between power in a lower HR Zone than 4 and actual threshold performance (of course, we need to ask ourselves: what are we actually calculating?). So if you knew, for example, that the rider’s FTHR is at 180 and the current interval was performed at 170, you would have a factor k indicating possibly higher threhold. I also think this factor should be variable and increase in conservativism the further you are from LTHR and/or the shorter the interval, so you wouldn’t fool it with a 5min or a zone 1 effort.
  • What I was also thinking about (with a possibly easier implementation, but different output) would be to create an efficiency vs. duration curve. Then, efforts can be compared to that curve and the result used either as it is or extrapolated (in moderation :smile: ) to actual FTP. This could be done either with data from the whole athlete database (taking into account that efficiency is also strictly individual) or by comparing to the athlete’s past results.

I’d so love if we can develop some algorithm that does it!

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David, did this ability get nuked sometime since January? I can’t seem to find a way to reset it now after being able to do it back in January.

Yes it is still there :slight_smile: Choose “Add Calendar Entry” and change the “Category” drop down to “Set eFTP”.

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Doh, scroll down Rob! Sorry for the bother!

Thanks,

I don’t know what I done a few weeks back (I did delete old seasons). I train of 260w currently and eFTP was calculated at a realistic 262w and after I deleted the seasons e’FTP went to an unrealistic (for me anyway) 303w. But Ive reset it like above and changed the default eFTP calculation length in the settings from180s (3mins) to 600s (10mins) :slight_smile:

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I did not know about this feature, pretty handy.
Curious why you didn’t implement an eFTP decay (like Xert has) I would guarantee that the fitness signature (or in this case just the eFTP) does not become stale?

Lot’s of people had questions in Xert about what is the correct decay to set. But in general simply having ‘a’ decay would guarantee that your eFTP does not remain stuck at high levels.

Also, isn’t eFTP estimated only on the 42 days period?

There is decay already baked in, although not sure of the implementation:

You can also see the decay on the fitness charts - see in the below image how my eFTP has been decaying over the past 6 months (black line) as my Training Load has also dropped (blue line), although judging by my max weekly ride eFTP (the bars) the eFTP metric has been decaying slower than my actual threshold power…

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No it goes up if you do a max effort that gives you a better number than what you currently have. If you reduce your training load it does decay slowly. But the decay side of it is very hit and miss which is why there is the “Set eFTP” option.

I got sick (not COVID!) two weeks ago and then is no way my FTP is what my eFTP is right now :wink:

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I know if an athlete has been injured or sick that I would disregard that number, but people who are self coaching may find themselves in trouble if using that number to scale their workouts.
Also, just to clarify, the load is calculated based on eFTP or the FTP set in settings?

I think it would be good to have a certain amount to decay to avoid these cases.
These are the options on Xert (and there is a ton of discussion about these in their forum)

Load is relative to the FTP set on the ride which is taken from the FTP in /settings initially.

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Im trying to save a new eFTP, but its not saving, anyone any idea what Im not doing? Thanks.
Since writing this Ive realised that it is resetting, but ony in Bike mode, I use power for running and cant seem t change it from BIke to Run eFTP.
TIA

I’m afraid David forgot to implement this feature when he added all the running stuff.
You can change FTP by changing it on your last run activity. If I’m not mistaking, this new FTP will be used from that activity on. But for eFTP, I don’t see a workaround at this moment.