Building In Public
Introducing: Morning Stability
January 26, 2023

At Visible, we want to help you use data to better understand and manage your illness. Today, we're introducing a major update to the Visible beta app that will get us one step closer to achieving this goal.

We’ll be rolling this update out slowly over the next few days, so hold tight if you don’t see it in your app yet!

So, what have we been working on?

When you check into the Visible app each morning you’ll see a number that we’ve been calling the “Morning Pace" score. This score is intended to help you make sense of your body’s signals, and use data to help you pace your day.

When we first released the score, we knew that it wasn’t perfect. But we also knew that it was important to release it early, so we could collect enough data and feedback to improve it.

We’ve now collected over 5.5 million data points from more than 15,000 people living with Long Covid and ME/CFS, alongside hundreds of unique pieces of feedback from our beta testers. We’ve spent the last month analyzing all of this, and today we’re launching a new, updated score. We’re calling it Morning Stability.

Why are we updating the Morning Pace score?

Currently, the score only looks at one data point - Heart Rate Variability (HRV). It works by counting small changes in your HRV as a good sign, while treating large swings up or down in your HRV as a bad sign.

Having looked at the data, it generally holds true that this pattern correlates with symptoms. But it’s also clear that HRV alone doesn’t hold all of the answers. This means the score often gives results that don’t accurately represent how we feel, especially if it produces a high score on crash days.

What’s new in the Morning Stability score?

1. Focusing on stability

It’s clear from the data we’ve looked at that stability is an important predictor of symptom severity. Statistically speaking, the further your body’s signals are from their normal range, the more likely it is that symptoms will worsen on any given day. This means that stability can be a helpful tool when deciding how to pace.

Our new score, now out of 5, makes it easier to understand your stability each morning and make decisions based on it.

2. Including additional factors

As we mentioned above, the Morning Pace score only took into account HRV. From our analysis, it is also evident that changes in other factors are important when it comes to stability too.

For example, recent trends in your self-reported symptoms and your sleep quality also have significant predictive power. That’s why our new score now takes into account four key factors:

  • Changes in Heart Rate Variability
  • Changes in Resting Heart Rate
  • Your sleep score
  • Your symptom trends (from the evening check-in)

3. Increasing the “baseline” length

The Morning Pace score only took into account 7 days’ worth of data when calculating your baseline. We now know that this isn’t long enough, in part because it is significantly impacted by multi-day crashes.

For that reason, we’re now using your previous 14 days of data to calculate your normal ranges for biometric factors. This is a rolling time window, which means your baseline will stay up to date as you keep using Visible.

Note: We are working on a future version of the algorithm which will exclude any days marked as ‘Crash’ altogether from your normal range.

4. Showing our working

One of the issues with the old Morning Pace score was that it was a “black box”. This means it was difficult to understand precisely why it returned a certain score (for example, why did you get a score of 7 on one day and not 8?).

In the new version, we’re including every factor that impacts your stability score in a short “score summary”. This way you can easily tell how your score is calculated, and even decide which contributing factors matter most to you.

What else do I need to know?

We’re continuing to improve the new score

The Morning Stability score is in “beta”, which means (like the rest of the app!) it is still in its testing phase. We're still working on it, collecting data and doing more research to make it better.

We’ll continue adding new factors to the algorithm, as well as tailoring the score to different groups based on things like illness severity, symptom clusters and diagnosis.

In a future update we'll also be adding the ability to retake or delete your heart rate readings.

We’d love your feedback

Your feedback on what we build is invaluable, and we listen to everything we receive. Without it we wouldn’t have been able to build this new score at all, so please keep your insights coming!

You can get in touch with us either from the in-app ‘Help and Feedback’ section or email us directly at




The Visible Team

Stop guessing, start measuring.

Pace your activity, manage your symptoms and help move science forward.