What Your Readiness Score Means for Work Today

Quick Answer

Your readiness score is a composite output, and every brand builds it from a different recipe. Oura uses nine inputs, Garmin six, Apple three, and none publish how those inputs are weighted. Readiness works as a rough signal of the physiological load you are carrying, rather than a verdict on your day. The inputs underneath it tell you more.

Readiness scores have become something of a trend, with many people using the number to decide how to approach their day. But although the term is widely understood, the way it gets calculated is inconsistent between brands. Oura builds its score from nine inputs, Garmin uses six, Apple three, and Whoop calls the same idea recovery and reports a percentage. None publish the weighting, which is part of why one night's sleep can produce an 82 on one wrist and a 41 on the other.

That does not make the score useless, but it does make it a starting point rather than a verdict. Readiness came out of sport, where the recommendation attached to it guides how much physical intensity to take on. Applied to work it becomes less relevant, because knowledge work rarely depends on physical intensity. It depends on your cognitive profile. And whatever your score, there is almost always work that fits it, and finding the right fit means looking past the headline to the data underneath.

Every brand calculates readiness differently

Oura's Readiness Score pulls in nine inputs: resting heart rate, HRV balance, body temperature, recovery index, last night's sleep, sleep balance, sleep regularity, previous day activity and activity balance. Those inputs are viewed over different timelines: last night's sleep looks only at the past 24 hours, while HRV balance weighs your last fortnight against three months.

Whoop reports the same idea as a recovery percentage, built mainly from overnight HRV, resting heart rate and sleep performance, with respiratory rate, skin temperature and blood oxygen added on newer hardware.

Garmin's Training Readiness uses six factors: last night's sleep score, recovery time, HRV status, acute training load, three nights of sleep history and three days of stress history, with Body Battery running alongside as a separate gauge.

Apple's Readiness app uses just three sources and scores from 0 to 10: activity and training load, vitals including HRV, and recent sleep. Fitbit's works from HRV, resting heart rate and sleep against a seven-day baseline.

So the brands look at the same physiology but weight it differently, over different stretches of time. A score built mostly on recent training reads your rest day generously, whereas another that biases based on sleep regularity will continue to downgrade your readiness, long after a period of late nights.

Why the number deserves a pinch of salt

In 2025 a team led by Cailbhe Doherty reviewed 14 composite health scores from 10 manufacturers and found them drawing on much the same signals: HRV in 86 percent, resting heart rate in 79 percent, activity and sleep in 71 percent. None disclosed the weighting, and none had been validated against clinical outcomes (Doherty et al., 2025).

Two other things are worth bearing in mind. The score is relative to you, so a run of poor weeks pulls your baseline down, and after a while, your score will start to drift back up, recalibrating to this 'new normal'. A readiness of 90 after a rough month will feel like a very different day to 90 after a good one. Part of what feeds it is estimated rather than measured, since sleep staging is inferred from movement and heart rate, which is why we suggest reading sleep efficiency and total sleep time rather than relying on a sleep score alone.

None of this argues for ignoring your device, only for treating any morning's score as one reading among several and, as always, watching the trend rather than just today's number. If it has started to wind you up rather than settle you, that is worth understanding too.

The inputs are worth more than the score

When readiness drops, the useful question is which contributor moved, and most apps will show you.

HRV below your baseline usually reflects autonomic load: poor sleep, alcohol, illness, stress, hard training, or several at once. Where you are in your cycle will also impact your HRV. It is the most responsive of the inputs, and the noisiest.

Resting heart rate elevated by a few beats overnight is an early signal that you are getting ill, or that yesterday cost you more than it felt like. Skin temperature above baseline says the same, although for anyone who cycles it rises through the luteal phase anyway, which readiness algorithms do not always allow for.

Sleep duration and efficiency are the plainest numbers your device produces, and the closest it comes to a read on your cognitive bandwidth.

Which is why two identical scores of 62 can mean quite different things. One built on five hours of sleep and a heavy gym session calls for a lighter day and an early night, while one built on a rising temperature and elevated resting heart rate says you are getting ill, and only the contributors underneath will tell you which you are looking at.

What readiness was built for

These scores came out of sport, and that is where the logic holds up best, because training has a genuine intensity dial. A well recovered athlete can take on hard intervals, whilst a depleted one looks for an easy run, or a yoga session.

Even there, the evidence is modest. A meta-analysis of HRV-guided training found it improved aerobic performance but gave no significant advantage over a well-designed predefined programme (Medellín Ruiz et al., 2020). Later reviews have been kinder, and the fair reading is that training to your readiness has real but moderate benefits.

Work does not have an intensity dial

The fact is, you can not apply your readiness score to your work day. Firstly, because we all have to work, regardless, and secondly, because knowledge work isn't about physical intensity, it's about what cognitive profile you have today and how to make the most of it.

The question, therefore, is which work, rather than how much, and the answer is less obvious than it looks, because a low-arousal brain is not uniformly worse at thinking. Wieth and Zacks (2011) found that people solved insight problems more successfully at their non-optimal time of day, when focus was weakest, while analytical problems suffered as you would expect. A brain applying less top-down control filters less aggressively, which helps when the answer depends on a connection you would screen out.

So a low-readiness day is poor for anything needing sustained working memory and error-free execution: the financial model, the reconciliation, the difficult negotiation. It can be perfectly good for loose associative thinking, for reviewing something you are too close to, or for a first messy draft.

And much of what matters, the score cannot see. It does not know where you are in your cycle, which shifts your cognitive profile across the month, that your calendar has three back-to-back meetings before noon, or that the task you keep avoiding is awkward rather than hard. Readiness describes your body's recovery, it has nothing to do with your brain state nor the work to be done.

How to use this with Phase

Phase ignores your readiness score. It reads the data underneath instead, through integrations with Oura, Whoop, Apple Health, Garmin and 70 more, and turns that into a cognitive profile: what your brain is set up to do well today. Then it pulls in your tasks from Linear, Todoist, Notion, Asana, Trello or Google Tasks, along with your Google Calendar, and produces an alignment score for how well today's work fits it. Phase recommends the tasks that you will nail today, and how to manage your schedule today, and in the future.

• Works from the contributors, not the composite, so a sleep dip and an illness dip give different plans.
• Ranks your imported tasks by bio fit rather than deadline, and tells you which to start.
• Maps alignment across the week, so deep work lands in your peak window and lower-stakes work fills the flatter hours.
• Finds work that fits a low-readiness day instead of telling you to rest. Three priorities, one brain: pick one to nail, one to progress, one to push. More in wearables, sleep and energy.

The takeaway

Your readiness score is a compressed summary of physiological load. It's useful as a guide when it comes to planning physical recovery and training intensity. However, more interesting is to read it as a prompt to look at the contributors underneath. Readiness scores don't apply to work. Cognitive profiles have strengths every day, even if you are physically depleted, and the key is to finding the right work that fits.

Join the waitlist and be first in when Phase is ready to launch.

References

Doherty, C., Baldwin, M., Lambe, R., Burke, D. and Altini, M. (2025) 'Readiness, recovery, and strain: an evaluation of composite health scores in consumer wearables', Translational Exercise Biomedicine, 2(2), pp. 128-144. doi: 10.1515/teb-2025-0001.

Medellín Ruiz, J.P., Rubio-Arias, J.Á., Clemente-Suárez, V.J. and Ramos-Campo, D.J. (2020) 'Effectiveness of training prescription guided by heart rate variability versus predefined training', Applied Sciences, 10(23), 8532. doi: 10.3390/app10238532.

Wieth, M.B. and Zacks, R.T. (2011) 'Time of day effects on problem solving: when the non-optimal is optimal', Thinking & Reasoning, 17(4), pp. 387-401. doi: 10.1080/13546783.2011.625663.

Medical Disclaimer

The information in this post is for educational purposes only and does not constitute medical advice. Phase content on health, hormones and bio data is reviewed by our clinical advisory team. If you have concerns about your health or wellbeing, please consult a qualified healthcare professional.

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