Is managing recovery/fatigue just by TSS accurate enough?

Hello there,

I’m following a structured plan on TR since two months and so far completed all of them indoors on my smart trainer. I stick to the schedule and TSS ramp rates TR suggests and so far everything is perfect. I also use some Garmin devices, which use power and heart rate data to kind of guesstimate how much recovery I need. These recovery recommendations usually lie within the recovery days on my TR plan, which means whenever there is a TR training scheduled for the day, my Garmin usually tells me I’m good to go.

Yesterday however I tried my first TR training outdoor on the bike and send it to my Garmin Edge 530. Everything worked well, but I met a good friend I haven’t seen in years and we decided to ride along together. So instead if doing a 1 hour interval session with a TSS of 93, I ended up doing a two hours zone 1/2 ride with a TSS of 83.

The next training on my TR schedule is tomorrow, so today is a rest day - just like the previous weeks. As per TSS I’m good to go and even a little behind my goals (10 TSS missing from yesterdays ride).

However: My Garmin devices went full nuts and tell me I need 4 days of rest. (That’s the max amount…)
If I had completed the interval session as planned, Garmin would usually suggest around 24 hours of rest - so not even a full recovery day off the bike.

This leads me to my question/confusion: I know that a 2 hour zone 2 ride is completely different to a 1 hour interval session. But shouldn’t be the fatigue be similar when the TSS numbers are similar? And thus the amount of recovery? How come my Garmin tells me to recover 4 days, while trainings with similar TSS usually lead to a recovery time of ~24 hours? Does the ride duration really has such a huge impact even if I reduce the intensity by a lot?

I’m absolutely confused now. Maybe you can help me shed some light into this so I can make use of this in the future.

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No, not really. Though I can see why you would think that. FTP and TSS are useful constructs, but they arent describing physiology.

A 2 hr (z2) endurance ride is using almost entirely type I muscle fibres, a 1 hr sprint workout is using primarily type IIb.

So quite literally fatiguing different parts of the body.

I am simplifying to explain.


My Garmin has done the same thing… I listen to my body over my watch. And it’s ok to ride tired.


Don’t listen to Garmin. Every rest week ever it tells me I’m unproductive. Im only productive if I do vo2 max interval sessions. Its honestly their most worthless product offering.

  • TSS can only really be compared to other TSS if it’s achieved in a similar way. So comparing the TSS of two different 30/30 workouts is useful to see how each of them might leave you in terms of fatigue, and comparing the TSS of two different weeks of the same build block (with broadly the same structure each week) is good for knowing how the two weeks compare to each other in terms of fatigue. But the more variation there is in how you achieve the TSS, the more variation there is in how it will affect you. I can do 800+ TSS per week of cafe rides and exploring the countryside pretty much indefinitely, but 500 TSS of indoor structure is a lot for me.
  • TSS comparisons also go out the window completely if you switch from a power meter to heart rate for measuring outside (your post makes it seem like you have a power meter outside but you don’t say for certain). HRtss is a totally different thing really and often bears no correlation to real TSS. And that’s without even getting into the 'was your z1/2 ride REALLY in z1/2? conversation which I’m sure someone else will bring up here shortly.
  • I’m on wahoo for most of my stuff and only got a garmin watch recently so haven’t worked out the exact mechanism for this (whether it was an ‘auto pause’, a ‘resume later’, or the workout just running continuously), but a while ago I noticed all my garmin stats had been skewed WAY off and started investigating to figure out why. Turns out I had used my watch to record an 8 minute ride to the barbers, during which I must have been running late because my HR was like 150 when I got there. Then I sat in the chair for an hour (where my HR was presumably just above resting) and then rode 8 min home. Garmin gave me TSS credit for a continuous hour at 150bpm for that time when I was in the barbershop and thought my recording was ‘paused’. So if your 2hr ride with your friend included a cafe stop or a fair bit of chatting it’s possible that some part of the garmin algorithm counted that as part of your time in zone (even if it didn’t show up as actual TSS).

My personal experience is that TSS does not reflect how I feel, especially after anaerobic or above threshold workouts.
On the other hand, Garmin’s training load seems pretty good so the Garmin’s 4 weeks timeline of acute and chronic loads is useful to me, even when I mix multiple sports (running, tennis, etc…). Recovery time is more of an awareness of where you are so you can plan accordingly. I don’t think Garmin says that you shouldn’t train if you are not fully recovered or if you have many hours of recovery time left, especially if you know a rest day or recovery week is behind the corner.

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Point no. 2: Garmin is not telling you to rest for 4 days or 24hrs.

It’s taking into account sleep, stress, HRV, all sorts as well as the actual workout and telling you “how long it will take to fully recover for a work out of the same intensity”.

Nowhere does it say stop training, hide under your bed sheets until it counts down to zero :smiley:

It’s useful if you have a hard ride coming up or a race, or even another hard workout - it reminds you that you won’t be at full fitness and you can temper your expectations, or rest longer to be fresher for the upcoming task.


IMO, you need to stick to one training regimen / philosophy and ignore others.

If you are going to follow a TR plan, then follow the plan and do’t pay attention to the metrics or feedback you get from Garmin, Strava, etc. Different coaches constructed those concepts and likely have different philosophies, etc.

Which one you follow is up to you…but I would personally lean towards whatever company is focused primarily on coaching plans and expertise in that arena. But if you are piecemealing stuff from multiple sources, you are likely gonna get conflicting information.


100% agree with this.

You can forget about that Garmin score, it seems like a useful feature, but in my own experience it’s totally nuts.

Follow the plan, it’s that simple :raised_hands:

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Your Garmin probably just saw that you did more work than usual, and wants to bring it back down.

With recovery, I still believe we ourselves know better than any metrics. Do you feel tired? Is your motivation low, or are your legs heavy? Signs you need rest. The difficult bit is that pushing through a bit of fatigue is actually an important part of training, but pushing through too much is not helpful or even damaging.

That said, and in response to the title - for me, Trainingpeaks (TSS-based metrics) usually gets it right: if it says I need extra rest, I usually feel tired too. Any rides then just turn into a slog.

Thanks so much for all the detailed answers so far! These helped me to reflect on this and understand things better. As for the questions:

  • Yes, I do use a dual power meter while riding outdoors. I also use a chest strap for heart rate, so I have pretty much everything available that might be needed for calculating any metrics.
  • I’m not really fit, to be honest. Last summer my FTP was around 230 watts, but then I injured my knees on my job. I was not able to kneel, sit or stand without pain for months. There was no way I could cycle as it was making things worse.

It took almost five months, but with tons of physio, foam rolling, and exercises, the pain got manageable. In February this year, I started with a low-volume plan on Trainer Road, using adaptive training and post-ride surveys to adjust whenever I feel pain returning in my knee, and it works well. It started with an FTP of 105, which caused knee pain at first, but thanks to adaptive training, I can gradually increase the load on my knees in a controlled manner. AI FTP is now 159 watts with pretty much no pain, so there is hope for me to be able to properly cycle again.

The data of the ride:

  • Duration: 1 hour and 56 minutes
  • We did two breaks of 5 minutes each
  • TSS: 83, IF 0.63, NP: 100 watts
  • I spent 26% of the workout duration coasting, 35% in power zone 1, and 20% in power zone 2.
  • RPE was 2-3 (except for some minor hills)

Since I was unable to train for some months, I got some books about training. One of them is “Training and Racing with a Power Meter” by Hunter Allen. There is a table (7.3, chapter 7), that suggests that for TSS values below 150, recovery is generally complete by the following day. So with a TSS of 83, I wasn’t expecting my Edge to tell me I need 4 days of rest.

So I am not sure what skews this, but let’s be honest: I’m pretty much under-average fitness-wise and thanks to my knees I had a massive throw-back, so does all this fancy stuff even apply to me? Or should I just ride as much as I can without worrying about overtraining, TSS ramp rates, and all this technical stuff? (I find it very interesting, though…)

Cheers and sorry for the long post!

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I wouldn’t worry about what the edge tells you. It just realised you did something you hadn’t done in a while. It might not have been the TSS, but that you rode up a hill at higher power than usual.

I always have a litrle laugh when I make mine say “3 days” or whatever. For me it happens when I switch between my watch and my bike computer without syncing - like when I haven’t synced the watch for a while, but then use it for a harder ride, it’ll say 3 days because it doesn’t know if the other rides I’ve recorded on the bike edge. (I think it does know once it syncs to Garmin Connect, but I’m not 100% about it)

There’s actually been some recent science on this.

Training stress metrics.

Short answer, they were all wrong in different ways.

The most accurate of all metrics. Session RPE. Basically, how hard it felt to you, the athlete doing it.

You the actual athlete have the best measurement device currently invented. How it felt, how you recovered from the effort over time. Let that always be your guiding light.

TSS alone can lead many astray. Many will not even admit it to themselves. They chase it. They chase CTL. They are both flawed metrics. If you are going to use a simple metric, use one. Use it with caution. Never let it override your own subjective feelings. They, more often than not, are right.

Is the TSS of a 5hr workout the same if you did it fasted, you crashed half way through it, you had no sleep, you just got divorced, it was 45 degrees Celsius, you forgot to drink…

TSS knows nothing about you, it’s an incredibly simple work vs time equation. We are not robots. We are complex emotional animals. All work we do is not equal. This is why TSS and all currently invented metrics fail. They need more data. Currently, they don’t have it.

You’re perception of fatigue is a skill you can enhance. Work on it.


Presumably factoring in a duration component, yes?

In fact, you could probably create a Gross Workout Exertion Score by graphing in-the-moment RPE and calculating the area under the curve.

The garmin body battery is only accurate-ish if you wear it all the time. In my case, I only wear it from time to time or when out on a run, so the algorithm seems to think I sit on my ass for 4 days in a row and then do a hard effort, hence the 4 or 5 day recovery time

Also, holy crap, a 90 tss 1 hr workout is brutal!

I go by a mixture of TSS, CTL and ATL as far as planning workouts, but nothing is more accurate than how I’m feeling. Anytime I’ve had a failed workout, I knew it wasn’t gonna go well right from the start. Don’t need a device or number to tell me it ain’t gonna happen!

From Mr. TSS himself, here’s how to relate RPE to TSS.

If you think about it, it’s perfectly logical that RPE based training stress is more accurate than purely power based.

  1. So many people don’t have an accurate FTP estimate (all FTPs are estimates). RPE isn’t affected by that, though you do need to tune in your feel of effort levels.
  2. Your true FTP for today is affected by many things like illness, life stress, sleep, nutrition. Basically if you can’t perform to your actual ability today then you’re accumulating more stress for the same training done on a good day. RPE auto correct for this because the same objective work will subjectively be harder.
  3. Once you really are in tune with training by RPE, you can’t really overtrain. Many people using power meters overtrain. Again RPE is auto correcting.

I really recommend that to use Kolie Moore’s FTP test and train by RPE mainly, using power as a calibration device for RPE and for data analysis after the training session / ride / race. Power is also useful during a race to reign yourself in.

Power is not the true compass for training that most people mindlessly follow. Every good coach talks about needing lots of subjective feedback from the athlete to properly guide them. Listen to your body first, power meter is second.


I do like KM’s prescription for endurance riding - “as hard as you can while still feeling easy”.

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Well, I guess I should focus on calibrating my RPE-meter. :grinning:

Can I still rely on TSS as guidance to increase volume and for recovery weeks? Because at the moment I’m on a beginner low-volume plan with 3,5 hours of training each week, currently in base 2, but I’d like to add some more rides (not just active recovery rides). Is it still advisable to follow TSS ramp rates while also cross-checking with RPE and how fatigued I feel?

First of all, the answer is no. Second of all, as I’ve said many times, even inexperienced cyclists intuitively know this is true.

For instance, imagine three cyclists that want to achieve a CTL of 100. They each adopt a differenct strategy. Cyclist A goes out every day and rides at 115% of FTP until Cyclist A accumulates 100 TSS. Cyclist B goes out every day and rides for 1 hour at FTP. Cyclist C goes out every day and rides at Z2 until cyclist A accumulates 100 TSS.

Which cyclist is more likely to achieve the 100 CTL mark? I would argue that really only Cyclist C has a shot at success. The reason is: not all TSS are created equal. VO2max work requires more recovery than Threshold work. Threshold work requires more recovery than Z2 work.

Every cyclist intuitively knows this is true. Even TRIMP (which TSS/CTL was copied from) contemplated this fact. We only kid ourselves with uniform TSS as a matter of convenience.

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