Hi
Is intervals.icu the most demoralising bit of kit out there? I went on holiday on the 10th June and at the time my fitness level was 76. I had nine days completely off the bike and came back with a fitness level of 62!! 3 days later after only a few turbo sessions I set a 10 mile PB (by 38 secs) on my regular course. I have now done a weeks worth of workouts (including that TT) and my fitness level is still shown as only 63!! This is very demoralising to say the least and what do I have to do to get it back up gain? I have attached a page showing all my workouts since I came back and a view of my previous and current fitness level chart. cheers
3 Likes
This should help:
4 Likes
Hey.
Training stress and CTL (chronic training load I think) are simply measures calculated by people a while back that can reflect where a person is at and while it can be used as a measure of fitness, itās definitely better to measure your fitness by riding and seeing how youāre getting on.
38s off your PB. Iād say your rest week and workouts before you did the TT put you in to a great fitness place.
Thereās a heap of reading on TSS/CTL/Form etc out there.
My view - sometimes these charts reflect a general trend in my fitness, but the actual number on a given week doesnāt really matter.
At the most basic level - do bucket loads of riding and your CTL will go up. Will you be fitter? Maybe. You could add 10 to your CTL by going on an 8hr ride Iād guess.
Strategic training though to achieve long term fitness goals tends to be the way to go, which sometimes sees an increasing trend for a while, then drops as you taper/recover ā¦. and repeat.
9 Likes
I can relate to that feeling. Especially since I am trying to up my fitness score up to 100 I learned how much training load it takes to level up and how quickly it drops with easy days or days off.
However, you need to keep in mind, that the fitness score (from what I remember) is more like a figure of how your fatigue and your training load relate. Or in even simpler terms it doesnāt tell, how fit you are, but how much training load you can handle at a given time. Thus itās no wonder to set new PBs with a slightly lower fitness score because that means you are relatively fresh.
4 Likes
Thanks, it does seem to favour long rides. It went up from 73 to 79 a week previous to my hols after a 100 mile ride. Interval workouts donāt seem to have the same effect no matter how hard they are. cheers
2 Likes
Your fitness is your fitness, congratulations on you 10mile TT PB. The numbers on intervals.icu are just numbers. In my experience they bear no relation to my real fitness.
4 Likes
What is WAY more important, per Coggins, et.al. is fatigue. Your CTL could be 100, but if your fatigue is -20, you arenāt gong to perform as well if your CTL was 80 with a positive 20 fatigue.
4 Likes
I stopped chasing CTL a few years ago. This year Iāve not signed up for any events. Much happier for it. I donāt get frustrated on holidays or vacations when my CTL drops. Wifeās happy because Iām spending more time with her and the family.
My original goal for cycling was simply to stay in shape and lose some weight. Somehow that got usurped by my competitive self, driven to do all kinds of endurance events. Getting angry when my wife scheduled anything on Saturday mornings.
I had no balance, the PMC chart ruled my life.
Iām not as fast as I was, but Iād never want to go back to chasing CTL. And itās flawed because gains come on rest days/weeks.
CTL can be a cruel tyrant.
11 Likes
I agree with the other commenters. The Fitness metric on intervals.icu is really just a number thatās telling you how much work youāre doing and doesnāt really tell you how actually fit you are. If you really want to measure your actual fitness then you need to do fitness test and time trials - like you are doing. So if youāre setting PRās then your fitness plan is working regardless of the amount of total work youāre actually putting in.
When I do a KOS attempt my Fitness score on intervals.icu usually jumps like 8 or 10 points. But Iām exhausted and not really any more fit. If anything, at that moment I am less fit. So, like any other metrics, it has to be taken with a grain of salt and in context with all the other work youāre doing and the numbers and other measurable metrics you have available.
6 Likes
āāWhen I use data,ā Humpty Dumpty said in rather a scornful tone, āit means just what I choose it to mean - neither more nor less.ā
āThe question is,ā said Alice, āwhether you CAN make data mean so many different things.ā
ā"The question is,ā said Humpty Dumpty, 'which is to be master. That is all.āā
I 
my intervals charts. 
(with respect to Sir @LewisCarroll)
5 Likes
As the old saying goes, āAll models are wrong, some models are useful.ā
You need to decide what real-world metric matters to you, (event, personal goal, etc.), and then see how your ability to perform corresponds to the numbers you see - not the other way around.
Your body may or may not be well modeled by intervals.icu, Xert, SYSTM, WKO, ATL/CTL/Form, et cetera. Population statistics do not tell us about individuals.
13 Likes
I totally agree with you on this! Every analytics tool I have says I am getting less and less fit. But Iām able to ride faster/further/harder.
A good analogy is this āitās less about the weight on the scale and more about how loose your trousers are gettingā
10 Likes
Thanks everyone, some really good analogies there giving me a more balanced view of where I am and what I am doing 
5 Likes
This was great thread BTW! Thanks to all.
Iām using Intervals.icu to see general trends, to get a reminder to take it easy a day to two if I dip in the red, and to gauge if Iām āfreshā enough to go for something more if I feel like. I love the graphs, but thankfully, Iām not chasing numbers! This is a good reminder not to.
7 Likes
Amen. 
3 Likes
I really appreciate the perspective offered in this thread. It reminds me of a friend of mine who struggles with insomnia. He uses an Apple watch or some other wearable to quantify his sleep. He is now obsessed with the data on his watch, and it has become totally disconnected from his actual experience. If he wakes up and his watch tells him he is not well rested, then that must be the truth, and he feels tired and moody the rest of the day regardless of what actually happened overnight. And his anxiety and poor functioning have gotten much worse because of it, resulting inā¦ Insomnia. I wish I could tell him to laugh it off and throw the watch in the trash, but he really is suffering because of it.
10 Likes
Several years ago I was interested in getting a smart watch that included sleep tracking, but after researching different models and reading more about it, I decided that the array of available metrics and analyses would be more likely to decrease my sleep quality rather than help it.
There is some evidence and research that shows this can be a risk when using them:
ā¢ That Sleep Tracker Could Make Your Insomnia Worse - The New York Times
ā¢ The Sad Truth About Sleep-Tracking Devices and Apps - The New York Times
The podcast That Triathlon Show also has some episodes where they talk about wearable devices for sleep tracking:
ā¢ Devices, apps, and technology for triathletes with Michael Liberzon, Andrew Buckrell and Mikael Eriksson | EP#253 ā That Triathlon Show ā Overcast
ā¢ Sleep - the foundation of health and performance with Dr. Charles Samuels | EP#216 ā That Triathlon Show ā Overcast
4 Likes
I like being able to see my approximate sleep time stats, but I long ago decided to use it only as nice info that gives me a good idea of the time I actually fell asleep and then woke up, but only as a relative approximation. Everything else it tells me is usually suspect. So, I can definitely see how it could drive someone batty if they tried looking at it too closely and relying on it too much.
3 Likes
Data should never be used in situations where the precision of the data, or the accuracy of the measurement or algorithm is not understood.
Manufacturers of these devices are not honest about it. Providers of analysis software need to be up front about their data sets. SYSTM is not a shining example here. Medical care often is not. And providers of popular āAIā software are certainly not.
Unfortunately, this is not something that is taught in elementary education.
4 Likes
I have used sleep tracking on my Garmin Fenix 6S since it was available as a feature. I find it helpful info, but itās not something that is āspot onā in accuracy. Iām certain of that from various perspectives, including my actual vs the itās determination of: sleep start and finish times, awake times, and at least occasionally, dream sleep times. That last one is harder to argue, one might say, but hey, Iāll argue that I at least SOMETIMES KNOW I had very active dream sleep.
I definitely agree that it is possible to get so hung up on the numbers from our devices that it does more harm than good.
And I also agree that we as consumers are not privy to as much information about these ānumbersā that are fed to us as we should be. And even though there are cases to be made about whether or not that information could be misunderstood, I still think it should be provided.
We are stuck ābuying a pig in a pokeā and when it squeals, we have no idea why or what to do about it! The seller of the pig wants us to tell everything and then, IF the seller is feeling agreeable, he or she MAY respond with some feedbackā¦ or may NOT.
But NO WAY is that seller going to tell us how WE could understand the Pig Latin our latest purchase is saying to usā¦
I will give SOME credit to Garmin in that they DO provide āInsightsā about sleep patterns, and what healthy sleep ālooks likeā and they DO suggest ways to improve your daily activities that may be contributing to poor sleep. These are pretty basic, but there are a lot of people that donāt read and learn for themselves, so some basics might actually catch their attention and give some help.
My takeaways have mostly been in the form of REMINDERS of things I already knew but ignored with great skill! Like exercising intensely late at nightā¦ or staying up much too late too oftenā¦ and other things I just kept thinking I was privileged and could ignore without penalty. 
I think the best graphical illustration tools Iāve used for overall fitness have been the Strava Fitness and Freshness tool. It seems to be pretty accurate in terms of what it really says, and as this thread illustrates, the value of these numbers to an individual depends on interpreting them in light of what the individual does know that Strava does not know, like how youāve been sleeping, whether youāve been sick, what life stresses are going on, etc.
So even though my Fitness number has fallen off of late, only I can understand WHY and whether or not that is something to be concerned with or not. And generally, the answer is, āNo, not really a concern. Pretty much expected.ā
Do I want to change it enough to address my sleeping habits? Do I want to be a little more disciplined about my training load? Do I want to incorporate more Zone 2 rides? Am I willing to do more MAP or AC or NM workouts?
All these things impact the ānumbersā Iām going to be showing next week or month. And mostly, I really knew that without anything telling me.
But getting REMINDED of what I knowā¦ well, THATāS something else altogether!
So I personally donāt MIND getting REMINDED.
3 Likes