How to determine TSS when riding outside

Hi, Hello and Hi everybody.
I would like to accurately add a TSS value to my outdoor rides imported to my calendar. My issue is I cannot determine hard, very hard, etc…
Could I use my heart rate found in my ramp test in any measure as a metric?
I am really not comfortable using perceived effort.
A power meter may not be to far away but then that is why I have TRAINERROAD.
The ability to add TSS is a huge win as we desire to ride outside as well. I have a goal now for next year and would like to take some of the TRAINERROAD training plan outside when possible.
Podcast are break up the monotony of the work ride. I laugh and I learn . TRAINEROAD offers a wealth of knowledge. and the opportunity to get faster.
Thank you for opening the door and not stopping there.

1 Like

Check out some books and online articles on the topic by Joe Friel and Andy Coggin. Chad referenced books by both of them recently as the are the OGs on this. If you google it up, you’ll find links to Friels articles on estimating TSS, including the formulas he uses with and without a power meter.

There is this calculator on the SpinLoose site, but BBW I’ve never tested it, or researched it.

FWIW, here is an approach to manually estimating TSS based on RPE, HR zone and time. i used this approach for a while before I got a power meter and while it is definitely an estimate it is not totally useless.

But – get a power meter! If you are serious about training it will be by far the best money you can spend (after a TR subscription of course). Aside from accurately tracking all your TSS, you can definitely do TrainerRoad workouts outside although finding the right stretches of road to match up with the intervals can be a challenge depending on where you ride.


Thanks all, I did enter TSS values from research that I am comfortable with as it offers a benchmark. Desiring to stay out of the weeds concerning power meters I would like to know @Nate_Pearson what device offered the power data when the guys did Tahoe, Carson, Leadville, etc… Essentially, what power meters did the podcast guys use when riding off road… road pedal power, chain ring power, crank arm power, hub?

This is an issue I too have. Going PM route is $$$ with multiple bikes to deal with. Plus how much abuse they can get when riding off-road. Getting an estimate will at least get the ball rolling.

Upload your ride with HR data to Trainingpeaks, and they will calculate TSS!


This is what I do whenever I ride my mountain bike. I send all of my rides to TP anyway and they’ll give you an estimate for any ride that only has HR data, it’s then easy to update your ride in TR with their hrTSS. You can do this with a free TP account and a lot of devices will automatically send your rides to TP.

1 Like

Thanks for this thread and I agree that it’s hard to keep up with TSS on outdoor rides. I have PowerTap P1 pedals for my road bikes but can’t use them on my gravel bike as I use MBT shoes.

I did a ride last weekend that I’ve just got no clue how to estimate. 2 hour ride, 24 miles with 2 significant climbs and descents. So one big climb working my tail off…then descend for a good while. Then a KILLER climb for 45 min and then more descending that’s nearly no effort on the legs and done.

@kjtrailrunner and @dprimm

I know Nate uses a Quarq power meter on his MTB and used to have an SRM. Chad has a Quarq and Jonathan uses either a Quarq or a Stages. The Stages power meters are crank based while the Quarqs and SRMs are chain ring based. These power meters do not take more beating on the trails than when they are used on the road unless the bike goes tumbling and the power meter hits a rock or something. That said, this still isn’t any different than if a road bike hits the ground.

Upload your workouts/Rides to Strava. they will give your TSS.

1 Like

Woohoo, I added hrTSS for many of my outdoor rides to the calendar.
I have come full circle with my reasoning to join TRAINERROAD some years ago. I had all but pulled the trigger on a pair of power meter pedals yesterday and even spoke with customer service for that brand. Using info from this thread I added my TSS. This ability has offered relief that I didn’t need to get the pedals as more would never be enough for me thinking I now would need a hub power meter, SRM or Quarq for my MTB’s and adventure bikes.
Years ago I looked at a graded exercise test and TRAINERROAD offered me the ability to capture those metrics. Someone, then, would have had to assist so I settled for the 8 minute testing. Now the RAMP test captures all without assistance. So I am set, I am ready to begin training for 3 hour MTB races in January starting next Tuesday.
I do wonder, once I prove hrTSS and power meter derived TSS to be close, should I expect a difference in some metric once the tire leaves the trainer and hits the earth. Basically said, should I expect power to run out sooner once I start pedaling my weight around?

Did you set it up automatically in calendar? Or go through TP/Strava/what?

I am anxiously awaiting the IQ2 release. Looks promising.

1 Like

Before answering, I went back to the forum rules to review don’t break the law.
There are several ways to input an estimated TSS value. It was mentioned early in this thread that Coach Chad referenced Joe Friel. Joe has a chart that matches RPE and heart rate to zones. I first started with this chart. I set the zones in my GPS/heart rate device from the max heart rate of my ramp test. The chart from Joe Friel shows examples of how to calculate the time in each zone to gain accumulative stress. My device shows the time in each zone. TRAINEROAD allows RPE entry, a custom entry or a power meter entry. The custom entry can come from a somewhat time consuming calculation, or from one of the apps you mention. A manual entry is required unless a power meter is used. One of the apps would only offer a TSS under a premium account. I know I don’t have the premium account and my rides do not show TSS. The other app does offer a TSS value. Having zones is a must for TSS to be calculated unless RPE is utilized.
I didn’t mention these apps but I do see in previous TRAINERROAD blogs how to sync.
I am comfortable using my max heart rate from my ramp test at this time as I have seen where FTP is usually 5 minutes from the end of a graded exercise test like the ramp test. The calculations that TRAINERROAD uses to get my FTP satisfies me. Basically, it is a benchmark for training. I did use RPE for a run that I just entered into my calendar. I will schedule my floor exercises and weights into the calendar which will probably be RPE entries.
Hope all this helps.
Dropping the mike here. LOL

I just manually updated estimated TSS for my outdoor rides using my TrainingPeaks hrTSS. What a time consuming process. Is there an easier route to edit rides in TrainerRoad? It took 7 clicks to manually enter the estimated TSS. Editing rides should be easier.

1 Like

Agreed. Either make this simple or add HR to TR and calculate like TP.


Getting out of the weeds here.
After thinking all this over, I am now not so comfortable estimating my TSS period. My head unit uses 6 zones and find my TP account which is configurable was set at 7 zones (1-5c). I just don’t want to spend anymore time in it. I am finding any estimating to be time consuming and I will probably do something to estimate knowing it is exactly that, an estimate. So, I agree with @STP “get a power meter”.

The fact is:
I will be using the TSS from TRAINERROAD virtual power with TRAINERROAD training plans for MY training.
Thanks all for your input. I had to get out the bush hog to get through the weeds. Ready for my training to begin next week.

I’ve added my outdoor mountain bike rides (no power meter, but have HRM) to the TR calendar.

For some of them, I’ve calculated my hrTSS using Training Peaks, and I’ve found that hrTSS can give some interesting/wierd results. For example, I did a 6hr race in August where TP calculated my hrTSS as 602 - which is “too high” i.e. there is no way I was riding at threshold power for 6 hrs.

For the 2017 LT100, TP calculated my hrTSS as 701, which is closer than the above to what I think is a “right” TSS, but still maybe a little high as this would have me at an IF of 0.72 for the duration of the LT100.

hrTSS is a useful metric to have, but for me, at least, I need to interpret it thoughtfully for it to be helpful.

Tss on a mountain bike is hard to gauge, even with a power meter you will have a lower power number than your hr or rpe will estimate. The power meter only measures effort at the pedals.

Meanwhile you might be beating up your upper body with rough terrain.

Agreed. Interesting and so true.
You may want to review post before this reply. I was wondering how to input to your post (pacing “The Snake”) and Biotenik brings a valid point relative to power verses Hr verses RPE for TSS estimating of outdoor rides. We both know those last 7 miles with all those rocks require more than power, hard on the bod. Just gotta get to the towers. (I do have 2 belt buckles).