TSS and Relative Effort when coming back from illness/ injury

OK, so making my way back from Covid and, with some mild lingering symptoms and loss of fitness/ strength, generally easing my way back in and occasionally proving to myself that my numbers have, not surprisingly, dropped! I’m trying to be wise and watching my RPE, Recovery, Sleep quality, Resting heart rate, HR responsiveness, HRV, TSS and Strava’s Relative effort etc when I suddenly realised:

  1. Strava Relative Effort (RE) - I’ve never really trusted it as I find just a few heart beats difference in the average HR for a workout can make a massive difference in the RE (e.g. doing two Z2 workouts of 90 minutes, both with similar TSS, and 1 workout has almost double the RE).

  2. My TSS is being calculated according to my pre-Covid higher FTP. So when I dial down a ride e.g. I dialled down the last 20 minutes of OL: Lac de Cap de Long this morning and am told my TSS for the ride is lower than planned/‘predicted’. The (not so) amusing side to this is that ordinarily it would be a solid ride but not a hard one, yet this morning I finished it wanting a bucket and feeling like I’d just competed FF. More concerning of course, and the reason for this post, is that the calculation of my TSS is erroneous and therefor my weekly TSS will not be a true measure of my training load.

So, other than “Do a HM!” or “Do a FF! Make it two!” what do people do? (Sorry, don’t feel up to either of those now …). Just take a punt and manually adjust 4DP figures? Do it more scientifically? Make an on-the-fly quasi-scientific calculation to weekly TSS?

Thanks in advance.


I walked for a month. Then I did like 2 active recovery videos a week for 2 weeks. Then I started a plan but did maybe 50% of the first block. THEN, I finally managed a full block of training but was so tired at the end I needed 10 days of recovery. Am mid way thru block 2 (on now higher than pre Covid power numbers) and coping. Just.

I’ve had mates who just truck on through and keep riding and they’re fine. I’ve had others who have been off the bike for months and are still battling to even do a recovery spin. I got better fast when I just did walking and nothing else.

When I did get back on the bike, I rode super gently until my HR zone and my power zkne aligned nicely. HR was a good 4 zones higher than power zone at first. Wheb it was 1 zone higher I started that first block of training. Now it is bang on zone, the lower end actually. Half Monty gave me my highest LTHR ever by a good 2 or 3 bpm. So I wasn’t quite 100% when I took it. But improving every day


I also wouldn’t trust Strava’s relative effort. They have shown over the years they have no interest in devoting time to analysis tools and would rather be facebook2.0 and let us post videos of our mid ride cake instead.

As for what to do about TSS/4DP figures.
Personally I wouldn’t subject myself to a 4DP test (or any other maximal workout) whilst still having some lingering symptoms.
If you know your 4DP numbers are set too high then manually lower them to something more realistic (err on the low side) until you are fully recovered and then do a new Full Frontal.

Finally, many platforms have a way to correct TSS by going back and applying a different FTP for a given date range so you should be able to fix any ‘wrong’ data once you decide on your new more appropriate figures.


Thanks @DameLisa. You definitely had it worse than me, and are doing superbly now. And yes, like you, I know someone that had only a sneeze or two and others that were quite badly knocked out for some time.

I think part of my ‘problem’ is that I never got that sick, felt I could get on the bike within a week but waited a full week and felt relatively good with a Recovery Ride on D8. Easy Recovery and short Z2 rides that week, longer Z2 rides last week (all these rides watching power/ HR zone match, HR responsiveness and recovery, HRV etc which were bang on after a few Z2 rides) and this week a bit of MAP. And that’s when I’ve realised I’m far from where I thought I would be, feels like not just loss of fitness but a cylinder or two down. Just writing this makes me feel guilty when you struggled far more, and others even more than you. Perhaps I’m just immensely frustrated after having a shocking year last year (shoulder injury and surgery, knee injury) and feeling I was really on track this year. Apologies if sounding precious and impatient on this one …

Thanks @AndyP. After writing this I was reflecting on how I recently hit my highest (so far) numbers and, with the feeling of the harder workouts, those numbers were still going up. It’s these numbers I know I can’t train to to (so usually dial down anything above a Z2 ride) but can’t bring myself to drop them within the app. Today I did almost an hour of tempo and sub-threshold before dialling them down. Foolish? You bet. I’ll up numbers in between tests if I think they’re wrong and now’s the time to drop them. And in reality I probably wouldn’t be far out as we get to know what we can and cannot do. I’ll stop being a fool!
I tend to track my TSS on HRV4Training, inputting the TSS from SYSTM so no ability to retro change there. Again though, I know my true TSS is higher and don’t need to see a number to tell me that (although my post is asking so obviously it would be nice!!!).

Thanks again.

Oh I know the feeling of impatience post Covid all too well. It’s the gift that keeps on giving. You feel fine until there is any sort of exertion. I had a week where all my numbers were fine and I felt fine but wasn’t fine for big efforts. Do another week of zone 1 and 2. Then try again the next week. The next week, don’t do full on workouts, do zone 1/2 with teeny tiny efforts like. EOS, Cadence Drills, Ignitor, Recharger, Primers.
Then the next week, try again.

I ended up following the return from covid protocol posted by Orla Walsh. It took ages, but here I am 4 months after Covid with higher fitness (just) than pre Covid. So being good paid off big time.


So this might not be what you want to hear–i know it’s easy to get wrapped up in the data and all the cool analytical tools these days–but i think TSS / ensuring the “accuracy” (I put that in quotes for a reason) of your effort-estimation tool is the least important thing that you’re dealing with right now.

Far more important is what everyone else has said. Ramp up slowly, go by feel. If i were you, i’d either ride outside or on level mode so that you aren’t locked into any particular power and can just go by feel. Until you are fully back, your number one priorit yshould be returning to full health and to do that, if you are feeling up for doing activity, you should be conservative with it and let your body guide you rather than power numbers anyway.

THEN far down the line, let’s talk about TSS. TSS is not a direct measurement of anything physiological. It’s an estimate subject to assumptions in any case. So in order to decide what to do with it and how, i would ask, what are you using it for? It’s not really “data” per se but rather an output of data and i know this sounds circular, but it’s really only useful to the extent it’s useful (if that makes any sense).

A few examples:

i. some people use TSS to plan their training ramp up and make sure they are adding training stress but not too quickly. This is irrelevant for you right now, you should be going on feel anyway until you are back. So, put this use case on ice.

ii. some people compare total TSS year over year to see, when i hit my highest power numbers, what was my TSS like going into it? When you take a 30,000 ft view like this, small differences in TSS are kinda going to come out in the wash. So sure, refine the TSS number if you can, but it’s not super important for this use case if it’s not perfect.

iii. are you doing something more esoteric like seeing how HRV relates to TSS? If so that’s cool, but you might find it’s just as useful to put an asterisk in your training diary that during COVID and immediately post, your HRV/TSS relationship is different. it probably is different anyway even if your TSS estimation were perfect.

Finally, if you do want to try to make your TSS more accurate, i agree doing a test right now isn’t probably the best idea. You might be able to get the app to calculate it better just by dropping your FTP. FTP is often easier to eyeball than other numbers. Like if you’re doing an hour sub-threshold and you are finding it hard to complete, your FTP isn’t probably much higher (right this second) than the power you sustained for that hour. You can make it better this way but again it won’t be perfect (but as noted, i think that’s okay).

Hope that’s helpful!

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I did the same thing when coming back from a near fatal injury (only by either luck or being a Sufferlandrian did I not go down the rabbit hole). Breaking a collarbone didn’t help either. That’s why I say each COVID-19 case will be different as well. Some bounce back in a week, others are down for the count six months later.
Here’s the real key, and you’ve experienced it. Do what you can.

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See Dame Lisa’s comments. Here’s the real ‘bottom line’, do what you can. If you can’t ride even a simple recovery ride, get out and walk. It will build up your aerobic fitness. Do strength and yoga. You’ll find that a simple clearing of the lungs and mind help.


The walking was like a cure for me. Bizarre but the more I walked, the better I felt. We had a walking challenge on at work at the time so that helped with motivation.


If you still have some lingering symptoms, your Lap de Cap Long session sounds a bit OTT imho. I can’t imagine that is going to help recovery.

I say this only because I am exactly the sort of person who typically acts like smashing out a truly hard session is the only way to beat a virus/chest infection/any other ailment whatsoever. On occasion it has worked (pure chance. I don’t think it works), but in the last year I’ve actually listened to my body more (!) and in a couple of instances have been super cautious.

I was lucky that my only covid+ve experience was virtually nonexistent - 2 days until a negative test and a mild cough for 24 hours, but I was paranoid that it was lingering and that I’d damage myself, so took coming back verrrrrrry slowly (relative to the mildness of my symptoms). In hindsight I may not have to do so, but I don’t regret it. Forget whether your TSS was “right”, go holistic and make sure the body is happy.

ALSO, though, I would mention that when I DID get back to full training, I then went all in, buried myself completly and needed time off the bike again to recover, pulling out of my A race (and quitting half way through my B race) because of the hole I was in. Don’t do what I did.

TLDR take it easy, and don’t sweat the big stuff. It will come.

Just this. I felt great after a few Z2 rides so headed harder. Mistake! Will dial down to entirely Z2 for another week and then do mini-intense workouts as you suggest. Will look at Orla’s protcol - thanks.


Perhaps, but what I need to hear so thanks.
I’m very aware what viruses can do to heart muscle in particular so I was ramping up slowly, feeling good, numbers good and so I thought I’d try some MAP sessions - BAM! Really surprised me.

I’ve become pretty good in making sure I use multiple data sources of which I place the highest value on how I feel (a learning curve with numerous errors experienced to get there). My frustration at my TSS being obviously so far off was to do with point i) using it to make sure I wasn’t ramping up too quickly (along with feel and other variables). I find feel very good during workouts, and then at the extremes in between workouts e.g. 12 hours later I felt super good or immensely c%)$. I don’t find how I feel that useful in determining a week’s or a fortnight’s load - unless I’ve really overdone it and then it’s retrospective. More experience needed I guess.

So this morning I dialled down my FTP and MAP numbers in the app and then dialled down OL: Nice to Menton (hadn’t done it yet, keep my workouts interesting) to make it a flat and easy Z2 ride. Felt good, HR responsiveness and recovery good AND a TSS that is closer to accurately reflecting what I did. Not for TSS sake, but to help me with your point i).

Thank you for taking the time to give such a detailed reply and certainly helpful. :pray:


Thanks Sir James. Part of my problem has been never being too unwell (except for the first few days) but not feeling 100%. And then thinking I was there! Yep, back to Z2.

Yes, it certainly was. I knew I wasn’t ready for 9 Hammers or Kitchen Sink, thought I was ready for LDCDL.

Yes, thanks. Don’t want to go there. I’ll head back to Z2 and build up volume before throwing mini-intense efforts in and increasing (appropriately) from there.

Thanks for taking the time to help - much appreciated.

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I am about 6 weeks in now, I could barely sit up in bed for a couple of days, My energy seems much better but any movement, even a visit to the loo, brings about the dreaded cough again, so actually exercising seems a distant dream

It will come back. Hang in there. Am 4 months post now and smashing it again. The patient part just involves a lot of lethargy and boredom


Start with walking. Short walks to begin and then longer as the cough subsides. If you can’t do this in a two month period, get to medical as you may have something else going on.


Sorry to hear that. Take care and you will get back. The fatigue afterwards is so common - even if you feel better initially you may find that little efforts bring it back. As regards the cough, there are various tricks the docs have now that will often ‘break the cycle’ so if that cough continues head in for some medical help rather than suffer through it.

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Will echo @DameLisa and others comments. It really does seem to affect everyone very differently, some brush it off without a scratch & others seem to really struggle to get over it (myself being one - 2.5 years on and still getting flare ups with my lungs/fatigue when I’ve done too much).

What does seem common for those that do take longer to shake it off, is when you rush yourself back you end up digging yourself a deeper hole to climb out of. It’s very hard not to be impatient and want to get straight back to what you were doing before or doing too much too soon, but throwing the numbers out the window for a while & just going by feel/listening to your body seems to be the best medicine. Just build things up slowly/light, give it a few days after you’ve done more than you’ve done previously to see how the body reacts, then re-calibrate and see if you’re ready for a little more or if you need to dial it back a bit again.

All being well you’ll be back to your previous levels soon enough, but patience will win this race. This is from someone who’s learnt the hard way (many times over) the last couple of years what happens when you get impatient :slight_smile: I’m still not quite back to my previous levels of fitness/strength & take longer to recover than I used to pre-covid, but very close & able train/ride with reasonable consistency now. It’s hard not to think had I approached my recovery in the early days differently, knowing what i know now would it have shortened that journey back considerably, but it is what it is & I’ve learnt to listen to my body a lot better in that time, so some positives to be taken from it.

Walking was great for me too and was all I could do for a long while. It was gentle enough to not push the body too much but enough exercise to help the lungs/muscles open up & did wonders for the sanity :slight_smile: