@Marco_Saraceno
From what I have read from Marco Altini the Readiness Score takes in a wider view than just the rMSSD. But this is Marco’s secret sauce as Garmin has theirs. So the tags & age also influence it for example. I am a boring retired teetoller, no kids with a very regular routine yet my HRV4 Readiness Score looks like a map of the Himalayas. So whilst the Readiness Score might not seem to change much, if you narrow the scale of the graph you will (probably) see that the daily figure can go above & below the 1SD band quite regularly to indicate a significant variance. If that is not the case for you then you are either a black belt equivalent in Transcendental Meditation or perhaps not varying your training intensity enough? If you look at my graphs then you will see that the Readiness does follow the rMSSD (red line) pretty well. As you can see it is about setting the scale (& height also) of the graph appropriately.
From Perplexity
what metrics does the HRV4 app to calculate its readiness score
HRV4Training does not fully publish the exact algorithm or weightings behind its readiness score, but the company has shared the main inputs it uses and the logic behind them.hrv4training+2
Main physiological metrics
HRV4Training relies primarily on morning resting HRV, especially time‑domain metrics such as rMSSD, taken under consistent conditions upon waking.[aiendurance]
It interprets this HRV value relative to your own rolling baseline, flagging when today’s reading is substantially higher or lower than your normal range.marcoaltini.substack+1
It also considers resting heart rate in the same “deviation from your baseline” way, since elevated resting HR with suppressed HRV can indicate higher stress or incomplete recovery.[aiendurance]
Subjective metrics
The app combines your physiology with your self‑reported “subjective feel” each day (e.g., how fatigued or sore you feel, sleep quality, stress, muscle soreness, motivation).[hrv4training]
Daily color‑coded advice and readiness‑type outputs come from merging these subjective scores with HRV/HR deviations, rather than from physiology alone.[hrv4training]
What it does not use
HRV4Training makes a point of not building in your recent training load or behavior (e.g., distance or TSS) into the readiness calculation itself, unlike many wearables that mix inputs and outputs into a single score.marcoaltini.substack+1
Instead, it treats training load as context you interpret alongside the physiological and subjective data, rather than a direct ingredient in the readiness metric.marcoaltini.substack+1
Practical takeaway
In practice, your readiness/advice in HRV4Training is driven by:
- Morning HRV vs your baseline.
- Resting HR vs your baseline.
- Your daily subjective scores (fatigue, sleep, soreness, stress, etc.).aiendurance+2
If you want the precise numerical formula (exact weights or thresholds) HRV4Training uses, that information is not publicly disclosed and appears to be proprietary; only the high‑level components and principles are documented.hrv4training+1