So it is looking at the whole night, not just the moment you wake up.

Right because your heart rate variability changes dramatically across sleep stages. If you woke up during a deep sleep phase, your baseline is different than if you woke up during REM. The old method ignored this. The new method weights the data based on sleep architecture. It is more accurate, but it requires more processing power on the device itself.

Does that mean battery life takes a hit?

It does, which is why the newer chips from Qualcomm and Apple are specifically optimized for always-on biometric sampling. You get longer battery life and more accurate recovery scores.

That is the healthy relationship. Use it to spot trends, not daily fluctuations. If your recovery score drops for three days in a row, listen to it. If it fluctuates randomly, ignore it. The signal is in the long-term average, not the daily snapshot.

And if the trend looks bad, maybe take a rest day.

Or investigate. See if you are sleeping better, eating differently, or managing stress. The watch is a mirror. It reflects your habits. If you don't like the reflection, change the habits, not the mirror.

Simple enough. But do you think these scores will ever be standardized?

Unlikely. Each company has its own proprietary algorithm.

That is the classic false positive. The watch sees a slightly elevated resting heart rate because he drank wine the night before, assumes systemic fatigue, and tells him to rest. But his muscles were fine. His central nervous system might be tired, but his physical capacity is there. This mismatch creates distrust, which is exactly what these companies want to avoid now that the initial hype cycle has settled.

So what actually goes into a score that works?

You need a composite metric. It starts with resting heart rate trend, not the raw number. Then you layer in heart rate variability over a seven-day window. Finally, you add sleep efficiency and, crucially, subjective feedback.