Intervals.icu interval detection and training tool

[davidtinker]

Is there a way that you can change/adjust the estimated FTP?

There is no way that my FTP can be 298W.

I was off the bike for some time and lost quite some fitness.

 

You can just ignore it and choose not to enter that as your current FTP. That said I am still tweaking this especially the decay rate and appreciate this sort of real life feedback.

 

On the 1st of May you did some good power and reached an FTP of 304w. That part I think is probably correct. You continued training at a similar level until approx 29th of May so the estimate remained at 304w. After that it started decaying reaching 298w on the 12th of June. You haven't been doing nothing over that time or it would have decayed quicker.

 

Its quite possible that the decay rate isn't quick enough. On the other hand should 2 weeks of half usual training load cause your FTP to drop drastically? Obviously if you were sick during that time the impact would be more but I don't have that info.

 

Any coaches out there have an opinion on this?

[shaper]

Article on decay rate of fitness through inactivity in training https://www.cyclingweekly.com/fitness/training/detraining-the-truth-about-losing-fitness-22330

[JohanDiv]

Currently you need at least 8 previous activities with power and HR and then Intervals.icu will use that data to estimate training load for activities with only HR. It basically figures out "training load / hour" for a given average HR.

 

I could implement a default model to use in the absence of any power data that used only HR. Will look into that. Would probably need to know your max and resting HR.

 

Thanks David. Great work by the way!

Say if I did 8 activities within the last few weeks with power and HR, will that estimate training load work backwards for activities of around 3-4 months back or only for future activities? Doesn't look that way?

[davidtinker]

Thanks David. Great work by the way!

Say if I did 8 activities within the last few weeks with power and HR, will that estimate training load work backwards for activities of around 3-4 months back or only for future activities? Doesn't look that way?

 

Thanks! Currently it only uses the model for future activities but I could do some work on that. More for the todo list

[davidtinker]

Article on decay rate of fitness through inactivity in training https://www.cyclingweekly.com/fitness/training/detraining-the-truth-about-losing-fitness-22330

 

Tx  .. this bit is most relevant to the current discussion:

 

Weeks 2-3

At this point, your maximal oxygen uptake 
(VO2 max, the prime measure of your aerobic fitness) will have declined by anything from four to 20 per cent. 

 

So thats a 4 to 20% decline in FTP after 2-3 weeks of nothing. The max decay factor in Intervals.icu is 0.998 per day but that gets adjusted up (less decay) if you are still doing some training. Thats a 5% drop after 21 days. Maybe I need to bump that up or make it configurable.

[madmarc]

So now that i know how to see Aerobic Decoupling, I spent some time reviewing my IDT sessions going back approx 1 year. I'm horrified to see they all "BAD"

 

I fon't have a power meter for outrides so i'm only looking at IDT sessions where i use TR with virtual power training sessions.

 

What am i doing wrong here ! surely these numbers should improve with 3 sessions a week. I'm sometimes not consistent with training due to work commitments and sickness, but hell !! i put in the work when i can, and would expect to see at least some improvement.

 

I read the article on this subject and i'm leaning towards my Aerobic endurance being K@K and thinking i should change my training plan on TR to focus more on this.

 

I started with Sweetspot Base 1 & 2 then went to Sustained Power Build when this finishes I start their Century plan.

 

Clearly i'm doing something wrong here

 

Your comments ? 

[Jaco-fiets]

David if I enter a new FTP does the system backdate the fitness data or does it take the new FTP into account for future activities

[davidtinker]

David if I enter a new FTP does the system backdate the fitness data or does it take the new FTP into account for future activities

 

It uses it for future activities. You can change your FTP on old activities and it will recalc training load etc and update the fitness chart. The "list view" on the activities page is handy for bulk editing.

 

If you change your FTP on your most recent activity it will also update your FTP in settings for future activities.

[davidtinker]

So now that i know how to see Aerobic Decoupling, I spent some time reviewing my IDT sessions going back approx 1 year. I'm horrified to see they all "BAD"

Your comments ? 

 

I don't know much more than what I learned from Joe Friel's blog. I personally mostly don't have the time to ride more than approx 8-10h a week. Not sure if there is anything much I can do about endurance for 4h rides with that

[davidtinker]

If you are one of the lucky ones with an estimated FTP of more than 600 be aware that it’s not going to last. Busy working on better power file cleanup and anomaly detection.

[Andrew_Smith]

You can just ignore it and choose not to enter that as your current FTP. That said I am still tweaking this especially the decay rate and appreciate this sort of real life feedback.

 

On the 1st of May you did some good power and reached an FTP of 304w. That part I think is probably correct. You continued training at a similar level until approx 29th of May so the estimate remained at 304w. After that it started decaying reaching 298w on the 12th of June. You haven't been doing nothing over that time or it would have decayed quicker.

 

Its quite possible that the decay rate isn't quick enough. On the other hand should 2 weeks of half usual training load cause your FTP to drop drastically? Obviously if you were sick during that time the impact would be more but I don't have that info.

 

Any coaches out there have an opinion on this?

 

Hi David,

 

My estimated FTP is fixed now. 

 

I checked this evening after my ride and my estimated of 235W is way more accurate compared to the previous 304W (one day...)

 

Keep up the hard work, really loving the website.

Edited June 18, 2019 by Andrew_Smith

[davidtinker]

My estimated FTP is fixed now. 

I checked this evening after my ride and my estimated of 235W is way more accurate compared to the previous 304W (one day...)

Keep up the hard work, really loving the website.

 

Thanks! Intervals.icu is busy updating everyones activities right now. I finally got some stuff working to automatically detect and fix power spikes in rides. Those make a real mess of the stats otherwise. I will post more info soon.

[davidtinker]

Intervals.icu now detects and fixes power spikes in rides. So if your power meter sometimes acts up it won't make a complete mess of your training load, estimated FTP and other stats. It compares your power output to what you should be capable of based on your the FTP for the ride. If your FTP is 300 and your power meter says you did 450w for 10 minutes (ha ha, nice try) then that is likely to be a measurement error. If large chunks of the ride are missing then your FTP is probably set too low and you should consider bumping it up. You can see the unmodified power trace by clicking the charts button and adding Raw Power. 

 

 

The screenshot shows this in action on a ride. The series of spikes to 1875w have been eliminated (the orange line on the chart) and the numerous drop outs have been corrected. There are some really ropey power meters out there!

 

The detection threshold is configurable per ride (click the 'Power spike' message) and in settings for future rides. But usually you should consider raising your FTP instead of raising the detection threshold.

[Vetplant]

Interesting thing I found after having flu the past week:

 

The Fitness chart and Activities Calendar does not progress if you don't register activities on Strava. I was curious to see where my Fitness, Fatigue and Form numbers would be after a week of recovery but I see the chart is "stuck" on 8 June, the date of my last activity.

 

Don't know if this is something you can look at in future, for it to automatically progress to the current date even if you don't log any activities?

[davidtinker]

The fitness chart should progress. I just checked mine now. The activities chart does not, I will fix that. Please mail me your Strava ID (david.tinker@gmail.com) so I can have a look at your chart.

[HdB]

It compares your power output to what you should be capable of based on your the FTP for the ride.

 

Below is my data from a hillclimb event a month ago, not even 4 minutes but super hard. I think the culling is a bit extreme here Do I adjust the detection interval or the FTP for the ride here? Power data is from my P1 pedals here.

 

 

Another one was a workout on Zwift, mostly steady over-unders. Afterwards, I still felt ok so I did a few max sprints (zoomed in on that bit below). Power for it is from my trainer, which is known to overshoot a bit on such short sprints. But the first two sprints especially have been chopped very low?