Yes. TrainerRoad uses a machine learning model to estimate TSS based on Heart Rate data for your outside rides when a power meter is unavailable.
Heart Rate-based TSS estimation is currently a web-only tool.
How to use Heart Rate-based TSS Estimation
Log in to the TrainerRoad website to access your career page. If we detect rides with heart rate data but without power, you'll be notified to use the HR-based TSS estimation tool upon logging in.
Current Career Page:
Adaptive Training Beta Career Page:
In order to estimate your TSS via Heart Rate, we'll need your max cycling heart rate and date of birth. If you're unsure of your maxHR, check your most recent Ramp Test to find your latest MaxHR data.
Note: if you haven't completed a Ramp Test and aren't sure of your maxHR, you can use another method to find an approximate maxHR: subtract 220-your age (it isn't perfect, but it'll get the job done until you take a Ramp Test).
Once you've entered your maxHR and DOB, you'll have three options to estimate TSS:
- Decide per ride
- Estimate all past and future rides
- Estimate future rides only
You can update your maxHR at any time. With All past and future rides selected, you'll be presented with the option to re-estimate all past rides with a newly entered maxHR value, or choose to only estimate future TSS with the the new maxHR value.
If you dismiss the original notifications to estimate TSS via Heart Rate, you can still access the hrTSS estimation tool from the Account section of the site.
If you find that you'd like to undo your Heart Rate-based TSS estimation, you can reset TSS to 0.
How to Estimate TSS per Ride
If you've selected to estimate TSS per ride, you can do so from the website on the Calendar, the Past Rides page, and from the Ride Details page for a workout.
Note: you can swap to the ability to estimate TSS via RPE from this modal as well as manage automatic Heart Rate-Based TSS settings.
How Heart Rate-based TSS Estimation Functions in the Apps
HR-based TSS estimation is currently a web-only tool. After using hrTSS estimation on the web, you'll find your Heart Rate-based TSS estimation when drilling into a specific ride in the app.
Note: HR TSS won't appear in the app if you're on an older version. Make sure you're on the latest version for HR TSS to appear.
How accurate is Heart Rate-based TSS?
No TSS estimate is perfectly accurate. The machine learning model we use to estimate TSS is significantly more accurate than existing heart rate or RPE-based formulas. For rides of an hour or less, the majority of estimates fall within a +/- 7 TSS of power-based TSS. For rides of one-to-two hours, most results fall within +/- 13 TSS.
Data from the model shows that accurate elevation and speed data can improve the TSS estimation.
Can I still use RPE to estimate TSS instead of Heart Rate?
Yes. You can still use RPE to estimate TSS. You'll find the option to toggle back to RPE based TSS estimation whenever drilling into the Past Ride Details for a ride.
Does Heart Rate-based TSS have any effect on Adaptive Training?
No. Heart Rate-based TSS won't affect any of the features of Adaptive Training.
Can I use Heart Rate-based TSS for an indoor ride without power?
No. Heart Rate-based TSS can only be used for outside rides with heart rate where power data is unavailable.
How do I know if Heart Rate-based TSS is working properly?
Consider the example of an hour long, all-out effort. This type of effort should have a TSS of 100. How far off is your TSS estimation? Contact firstname.lastname@example.org if you suspect issues with your HR-based TSS estimation.
My max heart rate changed. How do I update my max heart rate for future hrTSS estimations?
You can update your maxHR at any time for future estimations. View this section of the article for instructions on how to update it.
Does this feature work with all heart rate monitors?
Any heart rate monitor currently compatible with TrainerRoad works with ML-based TSS estimation. Some heart rate monitors may be more accurate than others, and the accuracy of the TSS estimate can be influenced by the quality of your heart rate monitor's data.