Daily VO2 max scores on Whoop could soon replace weekly estimates—here's why

The patented system could dynamically switch data sources to refresh scores more frequently

Whoop is exploring a new system to estimate the wearer’s VO2 max once per day by alternating between available data sources based on data quality.

This is a curious one considering VO2 max—a key indicator of aerobic fitness and long-term cardiovascular health—is one of the slowest moving health metrics, often to the frustration of users trying to boost it.

For the uninitiated, VO2 max is the maximum amount of oxygen your body can consume during intense exercise. A higher score often translates into greater endurance and the ability to push harder during exercise, but thresholds vary with factors like age.

Currently, Whoop estimates the wearer’s VO2 max once a week, typically on Tuesday, which aligns more closely with how slowly the metric changes.

However, in a new patent filing uncovered by Wareable, the company describes a method that switches among three data-collection methods to produce a daily score.

Switching between three modes of data collection

Whoop currently calculates a rolling average based on your activities (such as GPS-tracked runs), sleep, and heart rate metrics.

Yet, the patented system would use three different models for collecting the data and use the highest quality data available at the time to come up with the score.

The 'Passive' model, which relies on sleep and heart rate data, would be the least accurate. It provides the baseline when it’s been a while since the user has been active.

The 'Active' model would be activated if a user, for example, tracked an active run through GPS. This would provide greater accuracy for the VO2 max score.

The patent reads:

"When GPS-run features become available, e.g., after a user completes a GPS-enabled run, a user previously receiving passive estimates may be transitioned to an active estimate by computing the active model output and displaying it in preference to the passive output.

Conversely, when a member who has been receiving active estimates no longer has qualifying GPS-enabled run data within a lookback interval (e.g., ninety days), the member may transition to a 'passive-plus' mode in which the passive estimate is adjusted using an offset derived from the most recent time at which both passive and active estimates were concurrently available."

The key benefit appears to be the ability to opportunistically update the score using the most recent, highest-quality data source, rather than giving users a daily score like training readiness.

The changes are still likely to be small, but would give users access to the highest-quality data source mode rapidly.

Retroactively calibrating scores with clinical lab data

Furthermore, if the user adds a score from a test taken in a clinical setting, it becomes the gold standard and can be used to retroactively regrade historical scores.

Currently the input of a clinical VO2 max score is an idle metric that doesn’t affect the estimates created on device.

The patent adds:

"Regardless of which protocol is used, once a clinical assessment of maximal oxygen consumption is available, this may be used to improve the accuracy of estimates calculated using other techniques.

For example, in one aspect, a difference may be determined between the clinical assessment value and an estimate that was calculated using, e.g., the first model (as applied to data that was acquired on the same day as the clinical assessment). This difference may then be used to prospectively adjust subsequent calculations of maximal oxygen consumption with the first model and may continue indefinitely."

It’s this intelligent and automatic switching between a multi-state model that would give Whoop the ability to offer a daily estimate of VO2 max.

A smarter, data-driven approach to continuous tracking

On its website, Whoop explains how the current system works:

“Whoop uses a proprietary algorithm trained on lab-validated data to estimate your VO2 max. It analyzes your resting heart rate, heart rate variability, exercise patterns, and GPS-tracked performance, if enabled. The algorithm also accounts for natural changes with age and physical factors like height, weight, and biological sex to provide a more personalized estimate.”

While we’d expect the current system to stay in place for the time being, it’s interesting to see that Whoop is thinking more deeply about how it calculates and presents VO2 max data to users.

“This [system] converts what would otherwise be a single static estimator into a stateful, data-driven control scheme that adapts computation to the current sensor and context signals, thereby improving the reliability of the computed VO2 max value for real-world, continuous monitoring conditions and changing availability of external signals such as GPS,” the company adds.

Whoop declined to provide comment for our report.